A recent game by me

I played this game recently in a tournament. I was winning by a lot in the endgame but I had little time so I lost on time. Can someone give me some pointers on the middle game I played? Thank you!

Here is a pointer:
#include <stdio.h>
#include <stdlib.h>

int main (){
int x, *x ; \\ see the pointer ? I'm writing code on mobile to make this pun work.
char a[]="You played good but exchanging on f2 is wrong and you blundered a pawn on move 18/19 and you gave so much activity to your opponent.";
printf("%s",a);
return 0;
}

Forgot to mention that I was white in this game.

Oh. So a very nice game and some bad play from your opponent.
Also, please give the link with you playing at the bottom to avoid confusion.

You seem to need better time management most of all. You had a winning or better position for much of the game.