Very strange behaviour from a guy

Hi, I have a question about a guy I like. We study together at uni. At the beginning he flirted with me - talked to me, stared, smiled, went to events where I was, initiated physical contact many times etc. He suggested to meet but it never happened bc neither he nor I made any plans. I flirted back but sometimes I ignored him a bit because I didn't know how to behave (I didn't know if he liked me and preferred not to show too much). Once, after I was angry with him and completely ignored his messages, he told me that I never liked him. I was confused bc I wasn't sure if he liked me too. After a few months I got pissed bc he never invited me anywhere and I thought he played me so I decided to get revenge and ignore him as much as possible, to treat him like air. The guy was trying to talk and kept staring or coming over and standing next to me like he wanted me to notice him but I was still pissed. He would post things on ig like "People don't know what they have until they lose it" or "Don't trust someone who doesn't text back and is always looking at their phone irl." I felt it was about me. I thought he wanted me to feel a sting from a distance (this was during the holidays and we had no contact), but maybe it wasn't about me, it'd be a big coincidence tho. After he stopped with the staring I thought he may like me but is shy, so I asked him out out of the blue as I was sick of these questions in my head. He didn't really say anything, he didn't respond to that invitation. Eventually I started to say hi to him more often to see how he reacts, and he started talking to me more and more, but still looked a little scared of me. Then I asked him out for the second time, he said he'd love to but then he said he was travelling for the break, and ok, I believe he did. We would text a lot while he was away. He's been acting weird lately as he's been texting me every day and almost always starting the convo first, and we've been texting quite a bit. The problem is that irl he avoids me like the plague. Recently, for example, I was walking at uni and I saw him, I thought I'd approach and at the moment when he saw me he ran away almost to the very end of the corridor, and when I sat down he came back and talked to his male friends. He acted like I didn't exist. Another time he talked to me and we talked for a second, then I went over to him to continue and he quickly left and said we'd talk later. Ofc he texted me later. He sent me messages with hearts but I don't want to analyze such small things. Again he suggested to meet but this time said that my friend would also be invited. I replied that I preferred just me and him, and I was surprised that he wanted her to be there. I thought it was bc he didn't want to give me the wrong idea. He brainwashed me again. I was angry that he was avoiding me so much and I texted him not to run away when he saw me bc I wanted to talk and he said okay, we can talk. I also wrote it was kinda funny to text so much and not talk irl, and he texted me a lot less from then on. The next time he said hi and sat next to me in class, I already thought he listened to my request but after a while he went to sit somewhere else, just not to see me. I noticed he has a problem with sitting right next to me, bc if I was sitting at a distance it didn't bother him. Even earlier, I asked him a question and he walked by without looking at me, only from a distance after I left.. I was so upset by all this that I started being a bit rude, I texted him that I had enough of this behavior, asked if he was interested in taking it further, I added I had no time for indecisive manipulators, I took the initiative 2 times and still nothing, and that I would not entertain him again until his actions followed his words, I added that if not, he should go waste someone else's time. He went silent again. Then on his birthday I saw my friends posted a story on fb where he's in a photo together with my male and female friends. I must admit that I feel a little sad and I'm jealous bc generally he doesn't talk to girls, I've never seen him talk to these female friends either, except for occasional hello. Now he doesn't text at all. He used to he flirt with my friend when I saw it, or texted her to ask me something indirectly... It seems that he likes such stupid games. Irl it's like he's either avoiding me or his eyes look like a deer's in headlights when I say something, idk, he seems scared. And now I don't know what to do, whether to approach him one last time and talk it over (and ask him out for the last time), or to give up altogether and stop embarrassing myself. It's been going on for too long and I'm getting tired of it, it makes me feel like ****, I'm miserable all the time, but it's still bothering me. I plan to finally approach and if he doesn't agree to meet, to tell him what I think about this behavior and have him explain why he's doing such idiotic things and leading me on, tell him to finally be honest with me so I can move on. It doesn't help that I like him very much, otherwise I would've given up long ago. I don't understand the childishness. I don't think he has anyone either bc he seems awkward, but who knows, maybe I'm wrong and he's just a playboy. When he runs away from me like that I think that he doesn't care and wants me to stay away from him so I don't try to approach him anymore since it's discouraging. I think he may be too cowardly to hang out irl outside of uni but on the other hand I'm making excuses for him and still have some stupid hope that he will come around someday after he gets more comfortable.. I think he has self-esteem problems bc several times in texts he wrote negatively about himself, that he failed doing this or that, that he's stupid, that I wouldn't want to be in his position (ok..) Many times I wanted to let go and look around for someone more normal but there aren't many guys around, and I don't talk to guys I don't know, and he doesn't want to clarify at all whether he's interested or not, and besides idk why he suggests anything and then nothing happens. On the contrary, if he was indifferent would he run away like that? I feel like I came out of a psychiatric hospital bc no one has ever caused me so much uncertainty and emotional swings before, it's like a horror story. At the moment it's a waste of time and health. Sometimes I feel like he does it on purpose to show how much he doesn't give a **** about me. I started to suspect he was gay because he has gay friends and he looks a bit gay to me, but maybe I'm wrong. Sometimes I also think that he's off his rocker bc who acts like this when they have basic human decency.. A male perspective is especially welcome.