Analysis please?

 I'd like any tips/analysis you can provide of things i didn't see throughout. I realize 16. hxg5 was a mistake, so anything  I missed that could've got me out of that mess or could've done instead of that that would be better. Also, right  before I castled I wasn't sure what side to castle on.... how would you decide that in my situation as it seemed pretty locked up everywhere for hte moment. I ended up deciding on queenside because I figured putting the knight there prevented his pawns from advancing Thanks.

4. Bxc6 -definitely not a main line

11. Na4- not an efficient use of a tempo

13. c4-making a funky pawn structure, black has no d5 to push but you could have tried for d4!

14. h4 lost a pawn

19. Qf1-could have immediately lost the exchange

22. Bd2-further constricting yourself and losing a pawn

27. f3-could have blundered a pawn

38. Rd2-can lose the exchange

it's all downhill from there. I didn't spend too much time looking deep, so I probably missed a few more things.

Having said so many negative things, I don't want to seem like a bad guy- so I want to compliment your opening setup, although of course it wasn't book :). You at least built a solid base!

Firstly, 3. Bb5, isn't really considered a serious response to the Sicilian

Secondly, 4. Bxc6? is bad because it trades the Bishop for a Knight with no idea behind it. (you're lucky that your opponent played the weak 4...dxc6? instead of 4... Qxc6)

Thirdly, 5. d3 is weak. Your playing white, which means you should be trying for an advantage. your move accepts equality as the best result you can get.

Fourthly, 7. h3 was a lost tempo.

Fifthly, 10. g4?! weakened your K-side without reason. Remember, unless absolutely necessary, keep the wing-pawns home until the endgame! 

Sixthly, "a knight on the rim is dim". 11. Na4?! was not good.

Seventhly, 13. c4 severely weakened your 'd pawn'.

Eighthly, h4 was a decent idea (assuming the idea was to pile up on your opponents weak h-file) but it was poorly timed. You should have castled long before committing to a K-side attack.

Ninethly, Study tactics, everything else was tactical errors.

I know it's a bit harsh, but it'll make you a better player. Hang in there!

5. d3 weak pawn needed to move it d4.

8. black- rd8 move was a move by black to control the center of the board. move choices to defend-to gain control back you would have to sac the pawn and knight on d p or sac kb3.

general lee are you serious bb5 not considered a serious response?