I was a huge asshole and I don't know what to do about it.

Me and my ex started talking again around June of this year and things were going really well! Over some time I fell head over heels for him (again). Hell, we even went on multiple dates, but I don't know if all that went over his head or whether he was intentionally dodging my advances because I didn't call them dates. (But seriously who the fuck goes out for dinner with their ex and calls it platonic 🙄)

I was planning to officially ask him out again in early December, when a friend of his came up in conversation. He sent me some art that this friend (that I'm just going to call V) made of himself and V. The first drawing wasn't anything too conspicuous, but I brushed it off and tried not to let myself get jealous over it. About 10 minutes later he sent another drawing where a romantic connection was very obviously implied. That's when I got totally suspicious and decided to do some snooping around to see if I could find any of their accounts on tiktok.

Lo and behold, not only did I find V's tiktok account, but I found a video of them EXPLICITLY referring to my ex as their boyfriend AND HE WAS IN THE COMMENTS AGREEING! Not only that but that video contained one of the drawings my ex had JUST sent me claiming it was made by "a friend".

Being my calm and collected self, I chose the mature option of blocking him on all of my social media (Including fucking gmail for some reason?????) and crying for three hours straight.

A few days later at school I was talking to a group of our mutual friends when they asked what had happened. I wanted to keep it a secret- I really did, but they kept pushing the issue so i ended up spilling my guts about it under the impression they wouldn't tell my ex about it. Spoiler alert! You shouldn't trust teenage boys with ANY of your secrets because they immediately told him like, the minute school got off. 

Now my ex is just doubling down on the lie and saying that they aren't even dating which is just straight up NOT TRUE.

A few days after that I sent this as an apology for crashing out instead of communicating properly: 

Sorry to bother you with my bullshit again, but I’m really sorry for how shitty I’ve been treating you these past few weeks. I let rose coloured glasses cloud my judgement and when they shattered I made you the scapegoat for all my negative emotions and took my frustration out on you. This was beyond unacceptable and looking back I can see how much this must have affected you. If you want nothing to do with me that’s 100% understandable— you don’t even have to respond to this message if you don’t want to; but I want you to know that I sincerely and wholeheartedly apologise for my behaviour.

I hope that one day you start feeling better and that you have the time and energy to dedicate to someone better for you.

Since then he's clearly been super depressed and stuff. He always sets his status on his social media to something about how he is "gonna be left hanging new years

#canttakethisshitanymore ".

That's kinda the end of the story lol. I just don't know what to do about it because this happened like a month ago and it still really hurts. I just wish there was a way to make everything better, but there's not and I'm just at a total loss as of what to do. I tried reaching out to another mutual friend to make sure he isn't going to commit suicide or something, but I don't think that's helped, like, at all.

How do I either:

A. forget about him

or

B. Salvage this situation and make him not 100% hate my guts.