This is the danish gambit, I have to say if I played gambits, this would be one of my favorites.

I don't think Rf8 was a mistake for black (Re8 before definitely was)... the bishop and knight for the pawn and rook trade is about even.

12. e5 Ng8 (12...Nd5 13.Qf3+ forces the king to the center of the board or wins the knight) 13. Qc4+ Ke8... white is crashing in on blacks king, who can't castle, and doesn't have any developed pieces.  This looks like a quick knockout for white coming.

17. g4 wins the bishop

36. h6 isn't a great move, it already ties down the king to the kingside where it was protected.  Now if Kg6 the rook has to babysit the pawn or dump it. 

41. Rf8 wins faster

Overall, a pretty good game.  Stick with this gambit, I think it can serve you well!

Thanks for the tips, after turn 34 I was just seeing if I could promote (best part of the game)

On move 21, you should have taken with the Rook.

Most continuations lead to checkmate or loss of queen for rook/nothing, like moving Black queen onto the e file.

22…Qc7 23.Qe8+ (23…Kg7 24.Re7+!)  23…Kf6 24.Qf8+ (24…Kg5 25.h4+ Kh5 26.g4+ Kxh4 27.Qh6#) 24…Qf7 25.Rd6+ Kf5 26.Qxf7+

22…Qf5 23.Qe7+ Kg8 24.Rd8+ Qf8 25.Qxf8#

22…Qc8 23.Qe7+ Kg8 24.Rd8+ Qxd8 25.Qxd8+

lol nice engine font there