Anybody analyse, everything helps!!!

LOL, xD

9. Be2

It's better to wait to develop your LSB until it has a role to play. It's not really doing much on e2. A better move would be f3 to help support g4-g5. You can get your h pawn involved as well.

11. Nf3

As you mentioned this move is a mistake. You moved your Knight from its strong post in the center for no reason. Nb3 at least chases the Queen away.

12. a3

I really don't like this move. You don't want to move the pawns around your King when you are being attacked. This makes it very easy for your opponent to open lines towards your King.

14. Qxd2

It's very strange that your opponent traded Queens right after he opened up your King. 14. Nb4 would have kept the pressure up.

Okay so the general thing in your game is you made a lot of poor exchanges of pieces as well as a few moves mentioned by Vicarious. You allowed him to build up pressure and win a pawn on a3. I also believe it would have been more beneficial to if you played 32.Kc3 to go towards the queenside instead of towards the kingside as your knight is very well-placed on d4, covering most of the light-squared bishop's squares making it a pretty sad piece. Just my first thoughts after glancing at the game.

you shouldn't have moved your knight back when the queen threatened it. I would've also waited to castle to build up an equal starting position to them

disregard the knight comment

you let them open up their entire back row too, almost forced them to

Treating this as a puzzle and not moving anything I got 32. Kc3 Bd1 33. Kb4 Bg4 34. Kb5 Bh3 35. Nb3 Bf1 36. Nc5+ and since 36...Kc7 37. Nxe6 is check, White is pushing his way in.

This is blindfolded, but it is probably something you should be doing.

Well played.