I want to improve.


The d4 pawn is bad because it is vulnerable. Not having much to do with an endgame. Bad blunder and Queen trading was a bad idea. You get doubled pawns.

First off, good to play slow games:
join this group to find more partners for that:
http://www.chess.com/forum/view/livechess/interested-in-slow-chess?lc=1#last_comment
Second, you note that you've been studying positional concepts, which is all well and good. But tactics are by definition more important. Note even on move 5. Qb3.
When you got the B pair you didn't try to open the center. You could have got e4 in yourself; and in the endgame you just let him take away your B-pair advantage. Allowing him to get an outpost for his Knights also did not help.
Earlier, h3 does not 'restrict his Knight movement', as g4 is already defended by your queen. e4 there takes away his nice d5 outpost and NOW his Knights wouldn't have anything to do.
Qb5 as you noted is bad, but when you played Kc2 a few moves later you didn't even trade the b pawn for his d pawn! You probably still lose, but if you are playing, fight for it.
Hope it helps!

If you look at my stats graph, the big ratings jumps correlate to when I was using the tactics trainer the most.
Tactics, tactics, tactics, for us under 1800 players it pays better then any other study time.

If you look at my stats graph, the big ratings jumps correlate to when I was using the tactics trainer the most.
Tactics, tactics, tactics, for us under 1800 players it pays better then any other study time.
In that case, how can I use TT most efficiently - should I be looking at the analysis lines?
First off, good to play slow games:
join this group to find more partners for that:
http://www.chess.com/forum/view/livechess/interested-in-slow-chess?lc=1#last_comment
Second, you note that you've been studying positional concepts, which is all well and good. But tactics are by definition more important. Note even on move 5. Qb3.
When you got the B pair you didn't try to open the center. You could have got e4 in yourself; and in the endgame you just let him take away your B-pair advantage. Allowing him to get an outpost for his Knights also did not help.
Earlier, h3 does not 'restrict his Knight movement', as g4 is already defended by your queen. e4 there takes away his nice d5 outpost and NOW his Knights wouldn't have anything to do.
Qb5 as you noted is bad, but when you played Kc2 a few moves later you didn't even trade the b pawn for his d pawn! You probably still lose, but if you are playing, fight for it.
Hope it helps!
This is a great help. I've also joined your group for long games so I hope to improve by playing with some of your members.