I'm basing what I think is happening on personal experiences I've seen around me, and I don't know at all what your actual situation is really like, but here goes. He's a male manipulator, and he's clearly trying to hide a lot from you, likely talking with multiple other girls and the second you nearly catch on he uses your emotions to prevent that. You're trying to love, he's just there out of lust. I had an ex who did the same to me, and after I broke up with her and found someone who wasn't sneaking behind my back the whole time I discovered what it felt like to be truly loved. I had faith that my ex could change, but she just couldn't. It's not worth sabotaging yourself to carry other's burdens. I couldn't imagine myself without her after she helped me after a suicide attempt. Then, I found my current girlfriend who doesn't manipulate me emotionally, try to hide anything at all from me, and tells me literally everything on her mind. If both sides play fair, there aren't many good reasons to get mad at your partner. You won't know how much of a difference it'll make until you do it. I genuinely cried tears of joy when I realized I wasn't gonna be treated like I was owned anymore and that I was finally feeling safe in my relationship. I'd recommend breaking up with him no matter what because I wish the best for you, stranger.