6...c6 is passive. You gave up your bishop's pair with 3...Bg4 and 4...Bxf3 so as to control square d4. So you should have continued 6...c5 intending 7...Nc6 to strengthen your control over central square d4 and restrain his bishop's pair. 9...Qd5 is no good: the will have to flee further. 9...Qc7 was safe. 19...O-O just lets him take 20 Qxh6 for free, which he does not. The possibility exists for a few more moves. 36...R8f6 ignores the deadly threat 37 Rh4+ 37...Rh5 was imperative. You still had 2 minutes on your clock. You are a rook down. Earlier you missed some stronger defences too, but this was your last chance.