Search Results: how to help someone quit smoking

We went from meeting, to friends, to hooking up pretty fast but slowly slowly we've become more to each other. He told me honestly when I asked him, he was having sex with others before we became exclusive. He was honest: "we're not dating; I can do whatever I want." When I told him it hurt me that he got with someone else he was very apologetic and he told me he wouldn't do it again. Now that he says we're exclusive I'm so paranoid. Even though he's always in contact with me, I worry that he's cheating. I worry constantly. I get jealous, I get mean, I act unstable because I'm afraid he's lying. He's so kind to me when I act like this. He tells me he'd never hurt me. He tells me if he'd known I wanted to be exclusive earlier he would've been exclusive. He says he's sad that I'm sad and that he wishes he could hold me in his arms at that moment. Every time I feel guilty. He's unfollower all the half-naked women he used to have on instagram "from when he was single". He realized I didn't like the constant drinking and has been trying to slow that down. He's trying to quit smoking because I told him he needed to take care of himself. There are no signs that he's cheating. He is so respectful of me and patient with me and appreciative of me and he tries to prove to me that he genuinely cares about me and wants a future with me. I know I have no reason to think he's cheating. But I'm so anxious. I'm afraid one day I'll have nagged him too much and lose him.
I hate hurting him and picking fights because I'm scared. How do I get over this paranoia and let it go? I always regret the accusations and the mistrust but I can't help how I feel and I end up lashing out. Any advice?