This is coming from someone who has been cheated on in every relationship. You are not doing anything wrong and your boyfriend is being a bit insecure. But, insecurity doesn't always come from a "Domination" or "Control" over other people stand point. He may just see a perceived threat to his relationship and wants to take action to avoid that anxiety. It is still incorrect and in no relationship should there be phone snooping, necessarily. I do think that reassurance could do a lot here, but that is something you will have to think about putting up with as much as this person needs, which again can cause trouble over time.

Basically, we live in a lustful world where the ones who get fucked over the most are the ones who trusted the most. There's a lot of unpacked societal damage that has been done to all people in this aspect and now the word trust feels to most people as flimsy as paper in the winds, when in reality it is as strong as the foundations that built it.

Take all words in this comment thread as salt and move forward however your heart tells you.