Me (F22) really needs advice about guy (M23), how can I move past this (I was over it but now his lurking on my social media makes me feel weird?)

Hey everyone, I don’t usually come on these things a lot unless I direly need support. I am usually a person who never crushes on people but this person has not really left my mind. To start off, this story is really weird and to be honest maybe that is why I still think about it sometimes, but I would really like for me to forget about it and move on but for some reason it has recently creeped up again even though I forgot about it for months.
Basically, a long time ago (like Oct 2022) I had posted on reddit regarding an interaction I had with my crush. I had invited him to go to a local cafe with me to hang out/study, and it turned out to be a very weird interaction. TL;DR for this part, basically it was our first time talking and he started saying how he used to beat people/teachers, how he hates everyone, how he used to have anger issues, how he only tells me these things and none of his other friends.
Now, reasonably I was very confused and posted this on reddit way back when this occurred. I received over 50 comments of people telling me to run, never look back, avoid him, report him, etc, now I don’t know why but this didn’t really alarm me when he said these things because it was kind of funny (as if it was a joke). As a result, I kept hanging out with him (I’d always initiate and he’d accept), same place every time, for like 9 hours we would sit and talk (mainly him telling me more weird stories, things about him, stuff he doesn’t tell other people). Now, obviously this doesn’t seem just like a friendship, but alas this story gets worse. Every time we hung out, we wouldn’t talk for the next 3 weeks, and this cycle continued for around 5 months. Flash forward to Jan/Feb where I am honestly super confused and proceed to tell him my feelings/what are we sort of thing. I asked him to talk and we walked around for awhile until we found a suitable location, long story short though I was really nervous and didn’t end up telling him until late at night that day (so basically we just kept talking THE ENTIRE DAY happily and I didn’t tell him until he was about to leave – but I don’t get why he didn’t just ask at the beginning what I wanted to talk about? Like I keep thinking about it, cause its just so odd, usually if you meet someone to talk its like an hour/few mins tops but it would always turn into 9+ hour discussions. After I tell him, he acts happy and stuff but then says he isn’t looking for a relationship. However, he then says he liked me since the first day but he doesn’t want to break his or my heart?? Then he talks about marriage and stuff and how he doesn’t have a job or whatever. He also said if anyone else told him they liked him he would laugh but “because its you (me)” he said he respects me and wanted to talk it out. We then continue this discussion for an addition 5 hours until like 4am (I don’t even remember what we discussed cause he is SO CONFUSING and he is the most confusing person I’ve ever met). He said we could continue to talk the next day.
The next day, we meet again and once again this “discussion” turns into a 5 hour lecture essentially. He says how he “smashed” his feelings for me so he wouldn’t hurt himself, how he used to have severe mental health issues, and would only hang out with me in the weird intervals (2 weeks apart) to avoid falling in love with me. He then said that we could hang out in groups, but then said that if he saw me everyday he’d fall in love (his exact words). I asked him if he liked me now, he said “YESNO” I SWEAR, YESNO. Obviously, I ask him to be clear for me, he then says he used to, still does, and always will, but that he will not try to get to know me better. After like 1 more hour of me confused, he then says that he would try for me and then said we are on “Level 2” (whatever that means, he referred to our relationship in levels), and then we ended on a good note where he said we were officially together.
Then, we don’t see each other/text for 3 days, I see him on the third day and he basically tries to ignore me as much as possible. I ask him if everything’s alright and he says yes. Barely any talking, no how are you, etc, (HE WOULD ALWAYS DO THIS, where he’d go hot and cold). Then, obviously I’m a little confused so I give him 3 more days to think about stuff, then I message him if we can talk. He replies a day later and apologizes for the late reply and agrees. However, I was really busy that week with work (deadlines, projects, etc, that were very important), so I decided not to reply to the message for 3 days (also because he had exams and I wanted to just leave it for a little bit). After the third day when his work and my work were done, I messaged him about meeting that weekend (I didn’t apologize for replying late). No reply. I followed up again, No reply. To this day he has not opened it.
Essentially, I was over this and realized that 1) I am 100% responsible for my own misery in this situation, and 2) that he is not stable mentally for a relationship/friendship, and 3) low-key that he is dangerous as well. Yet, recently I began thinking about this again and I feel bad that if I replied sooner maybe he wouldn’t have ghosted me. It’s also because he ghosted me but always likes my pictures, views stories/posts, etc. You would think that someone that ghosted someone in this way would try to avoid the person they ghosted? Not him though. Any advice would be much appreciated, sorry that this is long I just really wanted to tell someone about this.
TLDR; was in a “situationship” with a hot and cold person who told me on our first hangout that he beat people and had anger issues, etc (more weird shit), who would hang out with me for 9 hours and then never talk to me again until the next time we hung out, again for 9 hours. Told him I liked him, he told me he doesn’t want a relationship but that he always liked me, is scared to love me, and that I was entering “dangerous territory” with him. Essentially, he was scared to let me in and he ghosted me in the end. He always stalks my social media (views stuff in a few seconds), and recently its been on my mind and I really need advice. Thank you.