I got to participate in a closed tourney about a month ago and I did relatively well.  I won against a class A, and two experts, losing to a master and and expert who was nearly a master.  I would like to know where I went wrong in this game

After 13.Qe2, maybe 13...c5, aiming for 14...cxd4 and 15...Rc8 or 15...Qc8.   

Perhaps 19...Rg8 of 19...f5 rather than 19...Qd7 which seems to waste a tempo. 

Instead of 22...Be7, perhaps 22...Rg8 and if 23.Qg4+, then 23...Kf8. 

25...Rh8 may be OK, but 25...Rg8 may be better or 25...Qd6 and 26...Rfd8. 

26...Qc7 looks too slow.  Perhaps 26...Rg8 or 26...Rhd8 or 26...Rcd8.  After 26...Qc7 27.d5 exd5 fails to 28.Nf5+ 

an alternative to 28...Bxd5 is 28...Qe5 and try to exchange Queens. 

or 30.Bxc8 and 31.Nf5+ 

33.Qxd5 and 34.Nf5 look strong for White. 

33...Qe6 is the losing move.  Black had to try 33...Bf8 and hold the h-pawn.

13...c5! opening the diagonal for your White-squared B & hitting Black's center. 13...Bd6? wastes Time & contributes to the weakening of your K-side(K-position).

20...Kh8 doesn't feel right to me, but on 20...Kh7, 21 Be4+ looks strong. Once your K-side got busted up you were in a heap of trouble especially against a Master. With that strong N(f5) there isn't much hope!