i think my(black) move no.. 34 must be Rb1 .. ??
UnExpectable game !

notice how in the endgame white gets his king into the action quickly by moving him into the centre to support his pawns while your king stays hidden and inactive in the corner? That is because in the endgame the king can become a major attacking piece. It is also a good idea when you are ahead in material to try to trade as much material as possible to simplify the position. I think 37...Rg2 threatening 38...Rg1 and the white rook, would have been my plan of action. I didn't look at the game in depth but these things jumped straight out at me.

You really needed to get your king into the action and focus more on attacking the c5/a4 pawns after your passed pawn got walled. Advancing the f pawn was what hung you, because you had nothing possessing f1, therefore queening there was out of the question, and advancing it did nothing to help you queen on h1.
That's how I see it playing out if you had attacked the a pawn instead of the f pawn with your rook. (sorry about the change in text format [left to centre orientation]. It changed when I placed the game and I can't figure out how to fix it hehe..)

You really needed to get your king into the action and focus more on attacking the c5/a4 pawns after your passed pawn got walled. Advancing the f pawn was what hung you, because you had nothing possessing f1, therefore queening there was out of the question, and advancing it did nothing to help you queen on h1.
That's how I see it playing out if you had attacked the a pawn instead of the f pawn with your rook. (sorry about the change in text format [left to centre orientation]. It changed when I placed the game and I can't figure out how to fix it hehe..)
whats wrong with 4.c8=Q?

whats wrong with 4.c8=Q?
My mistake, I stuffed up when I was doing the sequence. It was meant to be 3. ...Ra8 not Ra7.
3. ...Ra8 4. Kc6 Rc8 5. Kd7 Rxc7 6. Kxc7 and so on
Sorry about that

Good game until you reached the endgame then you kept your king too passive.
Like someone else mentioned your biggest blunder was going after the f pawn with the rook, instead you should have gone for the a pawn.

When you have a pawn about to get promotion and only a rook is blocking, this is the tactic you should do (look at variations):

I_GM you grabbed defeat from the jaws of victory...literally :)...here is what I could make out. 39.RD3 is a blunder RC3 is better threatening C pawn and potential discovered check in the next move and take C pawn...41. RxC7 was not required, you could have moved F3 instead and wasted his 1 move...43.F2 is wrong BF2 would have been better...44. G5 is a blunder BF4 was absolutely necessary to maintain your position...45. F5 is wrong F1=Q followed by BF2 was absolutely required to save the game...This analysis is only from move 39 and all prior moves have been ignored
Guys i was black ..... can u tell me my mistakes or blunders . can i was win this game .. ??