Hello ! These pawn endings are difficult to play, especially in blitz.
Just a few thoughts, en passant :
- I'm not sure 45...c6 secures the draw - what if for example white plays 46.d4 ?
- after 46...c5?!, you should check 47.Kh3 (if 47...cxb4 48.axb4 and 47...Kf4 48.Kh4!)
- the initial position looks winning for white
This was a 10 0 blitz game, so excuse the mistakes (but comment them freely)