As absurd as it sounds, I've always thought ships of the line to be 'one battle wonders' because of wooden hull, close range and massive volleys

I think that you're fairly far off base on this, actually. The wooden ships of the line of the period I study were battleships in every sense of the word -- both heavily armed and heavily armored (clad in wood) against enemy gunfire, and able to take an amazing amount of damage before sinking. Let's examine a couple of battles and then a couple of historic ships.

• The Battle of the Nile/Battle of Aboukir Bay, 1798, pitted 13 British ships of the line against an equal number of French ships (the French ships overall were slightly larger). The result of the battle was a decisive British victory; the British lost about 220 killed and 675 wounded against the French 3000-5000 killed and wounded and between 3000-4000 captured. But only two French ships were destroyed in the battle -- L'Orient as the result of a powder magazine explosion, and Timoleon, grounded, wrecked and set on fire by its crew before they escaped. Nine French ships had been battered into insensibility and surrendered. Three were later written off as losses, three were sold out of service, but three were bought into British service and used by its navy.

• The Battle of Trafalgar, 1805: 27 British ships of the line fought an allied fleet of 18 French and 15 Spanish ships. The French lost 10 ships captured (and Achille, which blew up) and the Spanish 11, with no losses for the British. Of the captured ships, several were lost or wrecked in a large storm that blew up after the battle, but one in particular illustrates the resiliency of ships of the line. Swiftsure was originally a British ship and fought at the Nile; she was next to L'Orient when the French ship blew up and took damage from that event. Swiftsure was captured by a larger French squadron in 1801, and served under the French flag at Trafalgar; she was recaptured by the British at Trafalgar and brought back into British service (as HMS Irresistible) and was eventually broken up in 1816.

Now, on to the most famous ship of the line of all, HMS Victory. Victory was laid down in 1759 and launched in 1765, and served in five major battles during her career: First (1778) and Second (1781) Ushant; Cape Spartel (1782); St. Vincent (1797) and Trafalgar (1805). She was badly damaged at Trafalgar, being dismasted, and was repaired afterward; she had also been repaired and partially rebuilt in 1797. Victory today is in drydock at Portsmouth.

So, no, wooden ships of the line were not one-battle wonders, and they would be repaired after battle and survive to fight again.

Good question - can I also ask if there is evidence of repair on HMS Victory or USS Constitution?

The favorite method of attack was crossing the T and firing into the enemies stern, the least protected area of the ship. Also the cannon ball had the whole length of the ship to do damage, especially the rigging. I have hear that the broadside was done to try to cave in the whole side of an enemy ship. If a only a couple cannon ball hit the enemy, the hull could absorb the damage, the wood would bend and spring back. If a whole broadside hit, it could exceed the breaking point of the wood and wreck the whole side. was that just a theory or did it work in action?