<human>: Could you distill the essence of the text into 1-3 sentences?

I lurked in this sub for some time and I hope you guys can help me out. I don't suppose people here say outright they are the antagonists of their own story, but in my case, it's true. I'm the bad guy and like Ralph in Wreck-it-Ralph, I'm just confused and just want my loved one to feel better around me.

Let me start.

My SO and I met in class. She's beautiful, and unaware to both of us we also both live in the same apartment. We dated for a while then became a thing. It really is a standard tale of boy meets girl.

Well, the problem, folks, started with me. I have low self-esteem, and unlike me who only had one ex-girlfriend, she had a lot of exes before. I felt inadequate, especially since I didn't have much luck with girls until I met her. I kept thinking she would cheat on me, or something, and that's where my obsession crept in.

I talked to her about this and she's sympathetic. She assures me there's nothing going on. I believe her, and I have been burned so many times in the past for thinking she's cheating on me when in fact she's not. But... there's something in my brain, something, I don't know what, something that triggers this shitty feeling on me. I don't know. I just want it to stop thinking for a second and let live. I just want to love my SO without her feeling I don't trust her.

My only problem is that I have long known this problem, been trying hard to ease it, and just keep failing. What do I do?

I think this is especially relevant, I have severe anxiety. I'm socially adept, but my mind keeps trying to see connections between things when in fact there's nothing. I'm paranoid, even before I meet my SO. I'm the type of guy who comes on time not because I value everyone's time but because I'm afraid everyone would talk bad on me when I'm late.
<bot>: Obsessed with my SO, thinking she's cheating when in fact she's not. How do I cure my obsession and provide my SO with a safe space of comfort and trust?