Some thoughts that occured to me looking through your game...
Move 14. ...Ke7 - did you consider 0-0. This would have been the standard way of securing the King, and I can see no obvious threat to prevent this.
Also, you planned Nc4 and then changed your mind because of Bxc4, but after placing a Rook on the c-file White has no way to defend the Bishop and after moving it, you win the c3 pawn.
Why was 16. Nc4 playable when you thought it wasn't a few moves earlier?
20. ...Kd6 moving the King to the centre in this position is a clear mistake - it needs shelter behind the pawns on h7, g7 and f7
35. ...Kd8, an alternative defenseive move to consider is Nd6, when with another King move to break the pin, the Knight is attacking the Rook.
40. Rf8+, alternatively, Rg8 wins White's Knight
One final comment, I thought you could have exploited your passed pawns on the a-file sooner by advancing them with your other pieces in support
Hope some of this may be of help.
Jason

i have hit a roadblock i have good postional skills decent tactical skills the i like the endgame but i just cant convert winning positions under time pressure and if im on the losing side like being a pawn down i just turn off and start playing passive chess waiting for my opponent to finish me off. any help on that matter would be highly appreciated !
edit: on move 22 i wanted to say couldnt