Mistake in the biggining :(

Losing the pawn wasn't the mistake, because almost all the pieces were still on the board when it happened. Trading pieces off whenever offered, was way worse. You needed to be more strategic in your trades, or avoid them. In my tiny opinion

Your opinion is wise, trysts.  Also, trading pawns that create a passed pawn for your opponent.  This was a difficult lesson for me to learn. Ha! I do not have that down pat yet.  

I remember playing an opponent that openly stated that he exchanged pieces every chance he had.  Not a wise thing to say, because I did my best to take advantage of it.  Any wise chess player realizes that there are times exchanges are not advisable to execute. Seemingly even exchanges are not always even when considering the total position of the broad.  A fact that that opponent did not seem to realize.