Couldn't White have just killed you with 11.c4? Then the Black Knight would have been chased away, and the f-pawn would have fallen, rather than you gaining a piece.
King's Gambit Accepted

After 11.c4 Black plays 11...Ndb4. If 12. Qc3 then 12...Bf5. If 12.Qd1 then 12...Bf5 12.Bxf4 dxe5 13.dxe5 Bxc2. If 12.Qe4 dxe5 13.dxe5 f5 14.Qxf4 (14...exf6 15.Qxf6) Nxc2. If 12.Qd2 dxe5. Black looks OK in all these variations.

I'm not much a of a KG player, but I would consider developing your king's bishop before Nc3 to cover e4. The same goes for move 6, where you advance e5 and just push his knight to a better square, and leave big holes on the light squares.

These Piece+Pawn Gambits are what I really like! ECO lists are 35+ piece+pawn-gambit variations in the King's gambit itself!
This game is delicious, but perhaps the R-sac comes too late for it to be called a proper piece+pawn gambit... [unlike the muzio, the salvatio etc. in the KG; most Wilkes-Barre lines; the Latvian fraser R-sac line [i think the exchange-sac line of the Latvian fraser is finally dead; though I am not convinced by Nunn's "refutation" of the entire fraser...]; the Latvian poisoned-pawn line...
I played an unusual line as Black in the King's Gambit Accepted, trying to fianchetto my queenside bishop. I didn't exactly have time to fianchetto the bishop, but it helped me find a mate after I trapped the enemy king in the middle of the board. I had to sac a rook to find the mate, but it was worth it. And my Queen Bishop helped, but it was on b3 instead of b7.