Pretty confused

Hi, I'm in a strange situation. I met my boyfriend while in grad school. He turned out to be an alcoholic getting his undergrad degree in his 30s while I was working on my Master's degree in my mid-late 20's. We haven't had the most perfect relationship. He had cheated on me about 1-2 years into our relationship. I've been a little possessive in the past which probably led him to this decision but I was quite distraught by what he did. We eventually got back together and agreed to move on from this situation. From my knowledge he hasn't cheated on me since. After he graduated, he got an internship at an amazing organization that hosts many interesting events. We've been fighting over me not being welcome to these events lately. I've come to about 2 and we've fought after them for various reasons. I should mention he interns in a place where a majority of women intern (him being an only guy in the department). Now, he doesn't want me to come to any of those events even if I'm really interested in them and just want to come to get out of the house. I have no idea if there's something going on with a fellow intern that comes to volunteer for those events with him or what it is. He tells me that he doesn't want to mix his personal life with his work life. But I still want to be a part of it. I told him I will just say hi at an event and go about my business and he seemed fine with that, but he still wants to go to the few upcoming events by himself...I just don't get what the problem is with me coming there except girls being there with whom he interns and whom he likes, possibly. I should also mention that unfortunately I'm currently unemployed. He knows about this since we've been living together for about a year and still, he is against me going to these events. I've explained to him that this may help with my job search as I network but he doesn't seem to believe me, thinking I'm there to spy on him.