Q+B vs Q+B

Here's a queen + bishop ending in a game I just played. I would like some feedback as to how I did.

The Q+B ending was basically "dead drawn".

36. e4 was a mistake, weakening the pawn chain. Black could have played 36... dxe4 37. Qxe4 Bb4 with some advantage.

37...dxe4 is fine, but not as good as playing it on the previous move.

37...Bg7 38. Qb8+ Bf8 doesn't help Black. White can choose either  39. Qe5 (repeating the position) or 39. Bh6 when Black is lucky to be able to avoid mate with 39 ... Qc3+ 40. Kf1 Qa3

The final position is definitely not drawn. It's a clear win for White after 53. Bf4 (preventing the exchange of the f pawn).

The final position was not drawn at all! It's a simple victory: White keeps the g3 square under control with his bishop to prevent ...g3, and then the king gobbles up the black pawns.

Black might have had an advantage in the queen ending, but it didn't appear to be easily convertible.

According to the in-game comment, White lost on time.

I would probably play 39.. Qd5, hoping for a drawn endgame where black is the only one playing for a win. I usually win such dead endgames, but white obviously has great drawing chances (if white doesn't take black has pressure on d4 and a centralised queen).

As already mentioned, the last position (after you lost your bishop actually) is completely won for white).

If we forget the blunder Bxd4 (which just shows that everyone should train their tactics) it was very nice played by black. Karpov would be proud if he was your coach.