Can you put some of the games you couldn't win because of this?
Tactical trade-off

Hmm i dunno if this i a good choice, but what i could find on the top of my list.
i think it is more of a live chess problem

While your opponent gets out a piece just to trade it with one of yours, you should just keep developing and you will have a huge advantage in development. For example;

Yes, 8.e5 wasn't too good. Develop and castle so you're looking better when exchanges start. Also 5.d3 and then 7.d4 was a waste of time. Leave it on d3, develop and push on, or go d4 in one go.
Exchanges into an endgame are not always bad. If you're active going into it, you'll be even more active after the exchanges.
Hey
I found that, when my games go over 30-35 moves i win almost all of them. My problem is that most people on my level of play, don´t let me play positional and just trade off when ever the chance is there. A good example is the Nf4, Bg5 - early center and bischop trade.
When i try to play defensive and remove my pieces to a safe square i feel like i am giving up "the good squares", and the center most of the time. Most instructional videos are with good players who intent to keep their pieces and not just slaughter them all off. So what can i do? ANY help is good :)
I´ve mostly played Queen- and Kings gambit