Is there a way for me (black) to win or its really draw?
I'm playing black and we end up with the position and then end up in a draw.
The White king is trapped - if Kh3, then Rh1#. The White rook cannot move off of the a-file (unless it's giving check at the same time) or the pawn promotes. So the good news is, he's stuck with just waiting moves unless he wants to play g4.
On the flip side, if you try to move your king to the a-file to chase the rook away, it has more than enouh squares to avoid your king. And if you try to bring it to the pawn, he can check your king until you're forced to retreat it from that area. So I don't think you can promote that pawn.
You can get your king to f2. But, you can't bring your rook to g1 to threaten g2 because his rook takes your pawn with check and you lose everything.
Pushing h5 doesn't seem to help; after gxh5 he can get his king to g3 where it can't be easily checked and it protects all of his pawns. (If your king is in f2 it only stops him momentarily - one waiting move with his rook, and you have to give up the square.)
thank you very much, what if my pawn is in a3 instead of a2?.
If the pawn is on a3 then his rook has the luxury of playing Rxg6 if your king moves away from that pawn - there's no immediate promotion threat. And if your rook goes to a2 it frees his king from the checkmate threat.
Also, I appear to have made an error in the line labeled "OK, let's try sacrificing the pawn"; 21...Kh4 is clearly inferior to 21...Kxf4 which wins. (I'm sure that's not my only error.) On the other hand, White doesn't have to trade rooks in the first place in that line - he could instead just check the king, forcing the black king to block the black rook or retreat, neither of which allows a pawn to be captured.