Distraught 😣

I'm currently distraughted with whats happening in me, my bf and I were all good when we're together actually even we're not there's constant call and update assurance and all. But recently when I knew some of the stories he told were not true it all changes. All the trauma on me came back, I tried everything to brush it off but it's really hard. He does assure me and thats for sure but it felt like something is wrong, that he's hiding something but I just don't know, however I can use his phone anytime. I don't know if this is just because I'm too traumatized on my past and what I just knew about him recently or is there really something wrong. I don't know if I'm the one in fault here. It felt like my stomach dropped everytime. But he kept on assuring me that he will never do such stupid things. I wanted to break things off cause this already affecting me/us, it causing my sanity but he doesn't want to let me go. I feel the love but it also feel something is off. Can anyone give me some advice?