How's my game? Where can I improve?

326 elo (rapid 10 min)

+5.42 to a draw.. how the hell am I supposed to see this?

These are the things that make me feel chess is just never going to "click" for me.

Why did this move by white bring the balance from 0 to -2.1 ? Why did nxe4 by black bring it back to 0? Chess.com analysis told me on the recapture, which it called a "miss", "You overlooked an opportunity to avoid trading the piece". .... uhhh ok?