Chernov, this is an excellent question. The answer is that it varied tremendously by social class, geography and education, but life was generally bad. Survivors of crippling injuries faced a world that did not accommodate their disability. They faced chronic pain. They faced post-traumatic stress. They faced suicide. They faced a crisis of masculinity, as many were unable to provide for their families in the same way they had before the war.
Brian Craig Miller's Empty Sleeves: Amputation in the Civil War South is an excellent book on this topic. Though it focuses primarily on the trauma of the amputation process itself, it does not neglect the aftermath. Similarly, Megan Kate Nelson's Ruin Nation: Destruction and the American Civil War has a chapter entitled "Empty Sleeves and Government Legs: The Ruins of Men" that is appropriate to your question.
In the South, an amputee faced titanic hurdles. "Damaged and defeated men," writes Miller on page 117 of his book, "coping with chronic pain, abundant health issues, and difficult transitions in a depressed postwar economy, found it often difficult to reassert their masculine identities."
Furthermore, there was strong social pressure in the South to avoid reliance on the state, whether for prosthetics or social welfare -- particularly so when the state providing that support was the one that had just defeated the South in the war.
And for many, prosthetics were not an option even if they had been available. Post-operative infections often left stumps unable to support a prosthesis. Instead, they limped around on crutches, worked with one arm, or simply made do. There are stories of men lashing themselves to plows, hopping behind on one leg, to keep a farm going. Many turned to begging, hoping their situation would increase the amount of alms. Many relied on friends and neighbors, contributing where they could.
Socially, Southern amputees were not rejected. As Miller writes on page 123, recounting a story told by Whitelaw Reid: "The crowds who gathered around the veterans 'seemed in nowise tempered by contempt for their lack of success.' In fact, Reid noticed that men dressed in their gray uniforms with missing legs and arms received extra attention."
The Confederate officer Richard Ewell was the prototypical example of a Southern amputee who returned from the war. Edward Pollard, who helped create the Lost Cause myth, once wrote that Ewell was "a spectacle of a worn and mutilated man ... but a nearer view disclosed a man remarkable even in the ruin of health and constitution, whose gray eye was as sharp and fierce as ever, and whose precise conversation showed that the vigor of his mind was as yet untouched."
Don't let this praise fool you, however. There were an extraordinary number of postwar suicides, even among those who were well off by postwar Southern standards. Miller shares the story of Bill Hicks, "a fine young man, an Apollo in form, and a model of strong physical manhood" who lost a leg during the war. After the fighting ended, he worked as a lawyer and seemed to have a strong practice going. Nevertheless, his missing leg bothered him, and rather than live as a cripple, a doctor noted, "in a fit of despondency, he blew out his brains."
In the North, amputees had more social and economic support from the state and society, even if they were lower-class. Theda Skocpol's Protecting Soldiers and Mothers: The Political Origins of Social Policy in the United States is an excellent work that explains how the veterans' pension system that sprang up after the American Civil War is --- rather than Social Security -- the true origin of the American welfare state.
The first disability pension system, passed in 1862, was graded by rank. Lieutenant colonels got $30 per month, for example, while privates received $8 per month. This relatively straightforward system didn't last long. Two years later, new laws mandated special benefits based on the type of disability, and these benefits were consistently expanded because of political pressure.
One-third of all Northern men between the ages of 18 and 44 served in the Civil War, and since these men made up a huge proportion of the electorate, there was correspondingly huge pressure to keep pensions high and keep them current. Furthermore, the pensions were initially limited to the most grievously wounded. In later years, this was relaxed to include all veterans. By the time of the Spanish-American War, spending on pension benefits was the largest single item in the U.S. federal budget -- bigger even than the outlay for the entire U.S. Army and Navy combined. In 1900, for example, William Glasson's Federal Military Pensions in the United States records more than 740,000 disabled Civil War veterans. The corresponding figures from 1865 showed only 35,880 veterans receiving pensions.
In addition to this generous social welfare system, the United States mass-produced artificial limbs for those who needed and could accept them. "Government legs" was a common term for the wooden limbs and crutches handed out.
Socially, Union veterans benefited from the Grand Review hosted in towns and cities across the country for returning soldiers. Visibly wounded soldiers got the loudest cheers and adoration, and when the cheering stopped, they had the benefit of knowing that their sacrificed limb was given up for victory in the war. Southern veterans didn't have that benefit, which contributed to their mental anguish.
Things weren't all tea and cakes for Northern veterans, however. They suffered through the same issues that Southern amputees faced: phantom pain, post-traumatic stress, and physical side effects. The issue of phantom pain in particular is one that comes up again and again in postwar writing.
This was a period when spiritualism and seances were hugely popular and in demand. The spiritualist newspaper Banner of Light frequently wrote about what happens when a person's soul and body become disconnected (i.e. when a person dies). This naturally lent itself to a question: What happens when a limb is severed? Is a portion of the soul severed, too? The issue of phantom pain seemed to lend evidence to this.
One of the macabre habits of Banner of Light was to write stories from the point of view of a soldier who had died. In 1862, it told a story allegedly contributed by "Caleb Wilkins" of the 11th Indiana. Drew Gilpin Faust covers the story in his her This Republic of Suffering on page 184:
"Wilkins reported that his leg had been amputated and that several days later he had bled to death ('The surgeons didn't tie the arteries well.') When Caleb met his brother in heaven and took a look at himself, he declared, 'that ain't my body ... I lost a leg, and this body is perfect.' His brother, already practiced in death, explained that Caleb was looking at his spiritual body. His 'spirit foot and leg' were perfect, and the pain he had felt after his amputation in his absent foot had been a consequence of the separation of his material from his spiritual appendages. 'The sudden severing of the mortal from the spirit leg caused pain, which lasted some minutes after the material leg had been amputated.' His amputation had been a kind of pre-death, a forerunner of the disjunction of material body and spirit yet to come. Wilkins and his brother helpfully provided readers with an explanation of the relationship of body and soul, as well as the assurance that no man, and indeed not even any leg, was truly lost."
In 1866, readers of The Atlantic were confronted with a short story, allegedly by a doctor who had his leg amputated as a result of a war wound. In reality, it was anonymous fiction that simply summarized so well the thoughts of the time that people took it as truth:
"I have little to add. I am now at home in the West, surrounded by every form of kindness, and every possible comfort; but, alas! I have so little surety of being myself, that I doubt my own honesty in drawing my pension, and feel absolved from gratitude to those who are kind to a being who is uncertain of being enough himself to be conscientiously responsible. It is needless to add, that I am not a happy fraction of a man; and that I am eager for the day when I shall rejoin the lost members of my corporeal family in another and a happier world."