There are a lot of books out there which were written after the war by German veterans, many of them being quite engaging at that. But while not universally so of course, a common, consistent strain you'll find is that whether explicitly or implicitly, there is a decidedly apologist bent to them. Some are consciously so (Such as convicted war criminal Kurt Meyer's "Grenadiers") while others simply are downplaying what they might have done, leaving the German war crimes to the SS only and awareness the Holocaust to distant rumors at best, if mentioned at all. For every honest account from the German side, you can probably find a dozen memoirs that have some sort of rosey tint to it. To be sure, I'm not saying that every German memoir is trash and you should burn the lot of them, just that you should approach them critically and be aware of their place in the historiography (if this interests you, I found it to be a bit heavy handed, but "Myth of the Eastern Front" by Ronald Smelser and Edward J. Davies, ll it nevertheless includes a good look at the whitewashing in many German memoirs).

So with that little preamble out of the way, let me now suggest a book for you. "A Stranger to Myself" by Willy Peter Reese is unlike most German memoirs you'll find out there in the honest and forthright perspective he offers on the terror of the Eastern Front, the crimes of the German war machine, and most importantly, his own awareness of complicity. In no small part this unique voice survived because Reese himself was killed during the war, in mid-1944. The diary that he kept was saved by his family, and eventually published in 2003 without any of the post-war circumscriptions that mark so many German first person accounts.

If you want to know more about how ordinary German soldiers experienced the war, I recommend two books. Both are fictional, but strongly based on the personal memories of the veteran authors:

• The cross of iron by Willi Heinrich about a Sergeant fighting on the Eastern Front (turned into a movie by the same title)
• The Boat by Lothar-Günther Buchheim about a German submarine (also turned into a movie)

Then there is an autobiographical book called Die Brücke by Gregor Dorfmeister (aka Manfred Gregor) about six teenagers who were ordered to defend an insignificant bridge during the last days of the war.

Last but not least I recommend the movie Downfall if you want to know more about the difficulties of restructuring the Wehrmacht during the battle of Berlin. It is based on a nonfiction book by the renowned historian Joachim Fest.

I know these titles aren't exactly what you asked for, but I thought they might be helpful.

some good recommendations already, I'd like to add the following:

• Gottlob Herrman Biedermann, a member of 132 Infantry Division, saw substancial combat in Ukraine/Crimea. His English-language autobiography is titled: "In Deadly Combat: A German Soldier's Memoir of the Eastern Front"

• Guy Sajer, an Alsatian of mixed Franco-German parentage, who became a journalist after the war, wrote a book based on his experiences as a member of Großdeutschland Division. The title of the book is "The Forgotten Soldier", it regularily appears on the Recommended Reading Lists of various branches of the US military.

• Siegfried Knappe was an artillery officer who chronicled his war time experiences from the Annexation of the Sudentenland, across France and Russia (and Italy, if I remember correctly), to the sieges of Breslau and Berlin. He saw the end of the war as a staff officer for Helmuth Weidling. His book is simply called "Soldat"

While Knappe's account is the only one that offers a look into the goings-on during the early (pre-Barbarossa) war, all three should provide you with a good look into the hardships of the later war years.

Edit: Should you also be interested in looking at the German War Effort on an operational Level through the eyes of a senior commander, I recommend you take a look at Erich von Manstein's "Lost Victories"