Why did I lost after a great start?

Hello, I don't really know why did I lost this game.

I play with white and I don't know when did I made the mistake. I made a great move in 20. Rxf6, but after that, with a material advantage started to fall. And I don't really know why?

Could you help me determine when were the mistakes done?

P.S. I played out of my mind in this game. He is a friend of mine, something like a 1600+ player, while I let the chess for years and this was one of my first games of the last years, give me a 1200. Maybe we arrived a moment when I didn't have more ideas? Should I have offered a draw?

Thank you very much for your help!

I can't see the game!

fixed! ;)

I think it might have been in your benefit if you would have taken the knight with your pawn on move 29. After you traded your rook for the other knight you really couldn't afford to trade him knights. Just my opinion, someone else might say otherwise.

Yeah, definitely 29.Nf5+ was when I threw the game. :S

Anyway, any comments on the style, strengths and weakness, ways of improving?

Thanks

"When you reach a winning position, the game has just started", some GM once said. 

His point is, when we reach a winning position we tend to relax, congratulate ourselves on all the good stuff we have done.

But at exactly this time our opponent is totally switched on - they are full of fear, and adrenalin.  

The result? They play best moves and we play slop, thinking the hard work has already been done. Big mistake. I know, from bitter experiences like yours:))

And yes, your 20 Rxf6 is definitely worth at least one exclamovitch!