Ending properly

This position occurred after a French defense my opponent were probably unfamiliar with .I thought to exchange the queens and the endgame would have been better for Black due to the good bishop and the good control of the files who force White's rook to defense.

But I had a feeling : "don't let him escape that way !"... And the spirit of tactics showed me the way !

That's more easy for you, you know there is something to find. Yet, it is not so obvious !

Note : if someone has time to lose, maybe he could check my analysis (see "move list") ? I feel as if I missed an easy win somewhere, but I cannot figure it.

Here's a simple gain of a pawn (and perhaps a little positional gain):

6... Qb6 attacking both the b2 pawn and the f2 pawn. After 7. Bg3, necessary to defend f2, 7... Qxb2 nabs you one point. Admittedly not a quick win, but it should at least give you a comfortable game.

True ! And White has to lose one tempo defending f2, so there is no compensation... Thanks !

@ Tigranlinflexible:

I think sheardp probably means 20... Rxc3 (which does indeed win immediately).

Nice, I didn't see it actually -- I tried a4 which is also easily winning, first a pawn, but also you'll queen shortly as far as I can tell.  Your way was much faster though.