I want to stop but how? HELP!!

Hey guys,

so over the past 7 years I have been in two very long serious relationships. The first one reallly fucked me over and just gave me reallly bad trust issues. My current boyfriend has not done anything as cheating (that i know of). But i realized I fell head over heels. I knew i should have given myself more time just discovering myself and learning how to love myself more. But obviously that wasn’t the case this time.

But anyway i’m in a year 2 of this relationship now. I feel as if i can’t trust him though. I have seen his phone in year 1 and saw him messaging other females ways that I just didn’t like. It brought me thinking to my first one. He stopped to my knowledge after arguments. He’s understanding. But like I just want to go through his phone and see. I haven’t but it has been on my mind. It’s bothering me.

Examples when i get iffy- he gets a text and i hear vibrations. i just wanna know who he’s texting. Am i wrong for feeling this way?

Btw we live together.

Steps on how to stop feeling or even thinking this way?

- I just want to stop thinking about what hes doing away from me. I want to focus on the present and not think so negatively.

Advice? Your story? Tips on how does one gain trust while being in a relationship?