11...b4 is probably good, but 12. Na4 Bxe4? 13. Bxf6 removes your defender and wins a piece. 11...b4 12. Na4 Nxe4 13. Bxe7 Qxe7 14. Nb6!? looks mildly irritating but still better for black.
11...Nxe4!? also seems like it works. I prefer the positions after 11...Nxe4 12. Bxe7 Nxc3 13. bxc3 Qxe7 or 11...Nxe4 12. Nxe4 Bxg5 (and 13. Nxg5 Qxg5 14. f3 where black aims for ...d5.)
16...Nc5 and 17...Bf6 feel right. Trading off white's b3-bishop is key in converting the victory, otherwise your f7 and e6 pawns would be paralysed under its glare. I'm not sure if the BxN trade was good for you, but it's certainly playable too, reaching a heavy piece endgame.
Endgames are really hard to evaluate without pouring hours into a single position, so here's a cursory look. Good technique, slowly squeezing white dry.
32...e3! looks like a winner. White is horribly besieged; 33. Qd3 e2 34. Re1 (or Rc1) Qxg3 is crushing; 33. fxe3? Qxg3 etc. Many horrendous things happen usually involving a combination of ...e2, ...f2+ and ...Qxg3.
35...e3! 3 moves after also is good. You recognise that the middle of the board is where the action is and drive forward bravely. Instead of e- and f-pawns we see e- and d-pawn smash white's rook. And "the rest is just technique" as the saying goes. Very well played.
Well, the computer analysis for free members reeks of dirty laundry, so I am posting my game here. I feel that I played particularly well for 15|10 time constraints. Let me know how I did!