Can't bring myself to stop seeing him, even though it's driving me crazy

My ex (29M) and I (26F) dated for 2 years before breaking up a few months ago. We lived together for most of that time, and we met at work and still work together. Throughout our relationship he cheated on me repeatedly by kissing and texting our mutual coworkers behind my back (several different ones, he has a reputation around work for hitting on everyone which is obviously humiliating to me). I'm scared that if I stop seeing him, he will start seeing other coworkers and I'll have awkward relationships with them, which is not a very rational thought process because he already HAS kissed a coworker and lied to me about it since we've broken up, despite me begging him to stop contaminating our workplace and sabotaging our careers by doing this. Still, I feel like continuing to see him gives me slightly more control of the situation, and if I give up my claim to him then I will be giving up whatever small amount of control I have.

I am extremely introverted, and I have a hard time making friends and connecting to people. When I attach to someone, I attach HARD, and I feel addicted to my ex. He is the only person I talk to every day, and when he makes me feel loved, he makes me feel SO loved. He does little romantic favors for me every day at work, and calls me after work every day to talk for hours, tells me how much he still loves me and doesn't want to lose me. We still hang out about 3 times a week, and I have so much fun with him, and really only feel happy doing something when I'm sharing the experience with him. The sex is amazing, I am more attracted to him than anyone I've ever had sex with, and I have a high libido so it's hard for me to go for a week without sex. I've tried meeting people through online dating, but I haven't felt nearly as attracted to any of them, and when I did meet a guy on there that I really liked, the sex was awful. It was supposed to make me feel more independent from my ex, but it backfired, and reinforced my view that my ex is a sex god and nobody else will measure up. Plus, he's my emergency contact. If my whole family died tomorrow, he would be the person I'd lean on. If I stopped talking him tomorrow, I would have no one.

When I'm with him, I'm so happy, and it feels like we're together and everything is right. I can accept that he wants to date other people in addition to me and that he's not really ready to be in a relationship, but he has no respect for my boundaries and has no problem lying to my face. He has lied to me so many times and I recount the lies in my head over and over again, and it has made me unable to trust anyone or believe that anyone else would not do the same thing to me.

I have become completely obsessed with the injustices he's done to me. It's the first thing I think about in the morning, it's all that I think about all day, and I cry uncontrollably all the time, even at work. I have been having major thoughts of suicide and I actually think I might go through with it. Part of why I'm still seeing him is that I know I would still feel this way if we stopped talking, but then he would be free and clear and wouldn't have to deal with the consequences of his actions and I'd be the one unfairly burdened by the pain. At least by seeing him, I can subject him to daily fights and reminders about everything he did to me, and try to make him feel the same pain that he made me feel.

Advice?

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Edited to add: I can't leave my job because they have given me a coveted position where I am training to be in my dream career, and they are financing my education and teaching me on the job. I paid my dues in a shitty entry level position for 1.5 years before they finally gave me this opportunity, and I recently got a raise. He is in a dead-end position at the company and could make more money as a waiter or bartender. It is so unfair for me to lose this opportunity because of him and I don't want it to be something else he takes away from me.