Bishop vs. 4 extra pawn endgame. Help.

This is a game I just finished, I have included the beginning if you are curious, we both made mistakes and i'm pretty sure I blew an easier win at some point.  

Anyway, when we got here I was pretty sure I was winning.  I've looked over it and I'm pretty sure that move 46 was a mistake, I think I should have took his pawn instend of defending my own. Then I should be able to make passed pawns on both sides of the board and I think that would be hard for him to defend.

The reason I'm posting is that I was having a hard time coming up with a plan.  So...  Any ideas? Strategies? Did I blow it? Should it have been a draw?  Thanks!

I think  46.kxf3  should result in black victory.

probable PV-46.kxf3 47.Bg4+ Ke4 48.Bh5 f5 49.Bg6 Kf4

Ok, seems my suspicions where right.  After I take that pawn there is no way he can stop me from advancing on both sides.

Thanks Fezzik. That helps, it seems the two passed central paws where my biggest asset.  I should of known that and looked for play around them.

Black should be able to win that if he plays accurately

3. ... Nxe4 looks extremely strong, just for future reference.  Very comfortable and White's queen will be strained, with nice play along the e file and threats along the e1-h4 diagonal.

Cool, I like that Nxe4 idea.  Thanks for the help everybody, I'm going to win it next time.

The end position is a draw, because if you head for the h3-pawn, White puts his bishop on f5. Otherwise, your pawns on d3 and c3 are blockaded.