So I have BPD and I think I'm in a toxic relationship.. 

We've been dating for 10 months and he's been acting very weird and been lying about multiple things ever since the start.

First of all, he had saved nudes from his friends on his phone. He claimed they were old and he forgot about them. He had over 10 secret albums on his phone with nudes. They were his current friends and exes. I was in one of the albums. He got angry and deleted them when I confronted him. 

He's been saving regular instagram photos of his other friends on his phone as p*rn material. He promised to delete them all and never do it again, but a few weeks later he had done the same. He had over 100 photos of his friends selfies on his phone. 

He promised he wouldn't see his ex girlfriend behind my back. But still he told her to come over late at night anyway. And she did. He claimed they didn't do anything, and she told me the same. 

He promised to not add girls from parties on snapchat that were flirting with him. He did that anyway. 

How do I know all of this? I hate to say it but I looked in his phone without him knowing. I've looked in his phone only around 3 different times when I saw all of this. And I confronted him about it every time it happened and he proceeded to get very angry at me and started yelling and insulting me. 

I tried to break up with him every time these things happened. He would first yell at me and then he would beg for my forgiveness and promise to never do it again. Yet he still does it. 

I think I know that breaking up is the only thing to get an end to all of this but I'm so deeply scared of losing him.. I love him so much and I don't want anyone else. I only have eyes for him. And that's why this hurts so much.. Because he tells me that he doesn't want to be with anyone else but me. He tells me that he wants to spend the rest of his life with me and that I'm his soulmate. He tell me that these things he does is his "private life" and that it doesn't have anything to do with our love. But I just don't understand that...

I would never do any of these things to him. I am deeply committed to him and only him and these things he's done hurts me so fucking much.. It really tears me apart. 

Can I really trust that he loves me and only me? That he wants to spend the rest of his life with me? Even though he's doing all of these things behind my back? 

I really need help... I'm really scared of breaking up with him because I don't want to lose him if he really is my soulmate.. After all, we really have such a fun and loving relationship when we're together. The only fights we've had have been because of these things I've told you...