Athough I play the Benoni now and then when my opponent refuses the Nimzo-Indian, I have no real knowledge of it - any Benoni players ?
But from what I can see :
9...Bc8 ? (undevelops) -> ...Qc7. Actually maybe even at move 8 ...Nbd7 was better with the idea that the queen on a4 prevents White to play a4, so Black can play his ...a6 - ...b5 without problems.
11...b6 is not very Benoni-like. The plan is ...a6-...b5, so I would rather take advantadge here of the fact White did not want to occupy e4 by ...Re8 followed by ...Bf5, in parallel to the ...a6/...b5 plan.
17...Be5 ? : I have no idea what Black's plan should be here, but certainly exchanging that strong bishop is not a good idea. Even if it's a "bad" bishop, he does a much better job than White's.
After that, once you lose a piece it's pretty much over... Nice try for a perpetual though (...Bxh3), I almost fell for it myself.
What can I say... Got barely out of the opening only to lose in a few more moves