OTB Game Analysis 3

This is my round 3 game from my most recent OTB tournament and you can find my round 1 game here.

I lost in the first two rounds and my opponent didn't show up for the third round. In round 4 (this game) I was facing the tournament leader with black, so I wasn't too optimistic. My goal was to play an interesting game and to play active chess.

The game

1.d4 Nf6 2.c4 e6 3.g3 d5 4.Bg2 Bb4+ 5.Nd2
I have never looked at this move, so I was on my own at this point
5...O-O 6.Nf3 c5
I played this since I didn't want to take on c4 and I am quite used to this kind of structure from the Tarrasch.
The most common move is 6...b6 where the game could continue in the following way: 6...b6 7.O-O Bb7 8.Ne5 Nbd7 9.Qa4 Bd6 10.Nxd7 Qxd7 11.Qxd7 Nxd7
7.cxd5 exd5
Here I decided to go for a structure with an IQP to have a bit of imbalance in the position. Taking on d5 with the queen was also an option but I didn't want a symmetrical structure.
8.a3 Bxd2+ 9.Bxd2

9...cxd4
The engine likes the move 9...c4 but I didn't really look at it during the game since it seemed to me like the pawn on c4 could become weak after white plays b3. However, the engine is (as always) correct and gives the line 9...c4 10.O-O Nc6 11.b3 Bf5 12.bxc4 dxc4 13.Qa4 Qd5 and black can apparently hold on to the c4-pawn. 10.Nxd4 Re8
Black should have developed the knight to c6 before white gets a chance to prevent it with Rc1. 10...Nc6 11.Nxc6 bxc6 12.Rc1 Bd7 and white's bishop on g2 is now attacking a protected pawn.
11.O-O Bg4
Again, black should have played Nc6.
12.Re1
12.h3 Bh5 13.Rc1 prevents Nc6 and white as a nice edge.
12...Nc6 (Finally) 13.Bg5 h6

14.Be3!?
At first I disliked this move since it looks very ugly, but it turns out that the white bishop needs to guard the knight on d4. For example: 14.Bf4 Qb6 and white has to play Be3 or take on c6.
14...Rc8 15.b4 a6
I played this move since I was unsure what to do and thought that taking the b5-square away from the white knight cannot be bad. The engine suggests 15...Ne5 16.Rc1 Nc4
16.Rc1
During the game I thought that this was already a mistake, but the engine pointed out that white can still hold the balance after this.
16...Nxd4

17.Rxc8?
This was white's mistake. White had to take on c4: 17.Bxd4 Rxc1 18.Qxc1 Bxe2 19.Bxf6! gxf6 20.Qxh6 = After 18...Rxe2 white plays 19.Rxe2 Bxe2 20.Bxf6
Black wins a pawn after the text move.
17...Nxe2+ 18.Rxe2 Qxc8 19.f3 Bh3

I felt that exchanging bishops helps black because it gets rid off white's bishop pair and eases the pressure on the d5-pawn.
20.Bxh3?!
20.Rc2 Qf5 21.Bxh3 Qxh3 22.Bd4 This line avoids the rook exchange and takes control of the c-file
20...Qxh3 21.Bd4 Rxe2 22.Qxe2 Qe6 23.Qc2
23.Qxe6 fxe6 24.Kf2 b5 25.Ke3 Kf7 wins for black.
23...Qc6 24.Qe2
24.Qxc6 bxc6 25.Bxf6 gxf6 26.Kf2 Kg7 27.Ke3 Kg6 28.Kd4 Kf5 29.a4 Ke6 30.Kc5 f5

And black wins because of the connected c- and d-pawns and white cannot take on c6.

24...b5?!
At this point, I made a big mistake in my calculations I saw the line 24...Qc1+ 25.Kf3 Qxa3 26.Qc2 Qxb4 27.Qc8+
But here I thought that white was still covering h7 and that I had to play 27...Qf8 28.Qxb7 Qd6 29.Qc8+ Qf8 (Again, I thought that this was forced) 30.Qxa6 and I felt that white has better chances for a draw due to my passive queen.
Instead of this, I could have also started a maneuver which I played later in the game: 24...Nh7 25.Kf2 Nf8 26.Qd3 Ne6 27.Bb2 Kf8 28.h4 Qc4 and black has improved his position quite a bit.
25.Kf2 Qc4 26.Qe3 Qc2+ 27.Kg1 Qc6 28.Kg2 Nh7

I was very happy with this maneuver during the game and it looks like the only way to make progress for black.
29.h4 Nf8 30.Qc3 Qxc3 31.Bxc3 Ne6 32.Kf2 g5 33.Ke3 f5 34.hxg5 hxg5 35.g4 f4+ 36.Kd3
When reaching this position I was a bit disappointed since I felt like I played all the right moves after the queen exchange, but I thought that this was only a draw.
36...Kf7 37.Bd2 Ke7 38.Bc3 Kd6?
During the game, I thought that the game was drawn since a couple of moves, but black has in fact a win in this position. 38...Nd8!

I thought that this was impossible since it allows the white king to enter on the queenside. However, black's pawns are faster.
39.Kd4 Ke6 40.Kc5 Nf7 41.Kb6 Ne5 42.Kxa6 (42.Bxe5 Kxe5 43.Kxa6 d4 -+) Nxf3 43.Kxb5 d4 44.Kc4 (44.Bb2 d3) dxc3 45.Kxc3 Kd5
And black is in time to catch white's queenside pawns.
39.Bf6 Kd7 1/2-1/2

After the game, I was happy with my play in general, since it was much better than in the first two rounds and I didn't feel that I missed any big chance. However, I was a bit angry with myself after I noticed my calculation mistake on move 24, since I saw the line but was seeing a ghost in the position.