What is the right thing to do?

Move on. Spend a year and get healthy, mentally emotionally and physically. You are not defined by your relationships. Really! It’s the best thing you can do for yourself.

By the way, no matter how good-looking this new guy is and how much you were attracted to him he sounds like a dud. You showed integrity by staying with the other guy and not dropping him for the new one. So now the new guy’s feelings are hurt.

He’s upset because you didn’t stroke his ego.

I agree with @snowberry – the events of the last year are ancient history. He has moved on. You need to as well.

Basically do nothing with Mark – in his mind, you had a chance with him and you screwed it up. Why would he ever want to take a chance on you again?

^^ From Mark’ point of view, that’s true. But if you followed that pattern with the next relationship, you’d dump the next guy as soon as someone else looked at you with desire. That’s no way to respect yourself or your guy.

Bottom line, Mark isn’t as cool as he thinks he is. He’s not worth it.

You don’t state what your relationship with Mark was prior to December. Was he part of your general sphere of friends, was he somebody you saw through work or school, or was he just some guy you met at Starbucks? You just call ita “great connection”.

If, and it is a big if, you really like Mark, give it a couple more days, after more than a full month off social media, and then reach out to him with an email.

Phrase it/title it as “start over from scratch”. And then ask him if he wants to start over again. But after a beginning conversation to establish where you both are at this point, tell him that his “December disappointment” is no longer a topic for conversation or comment.

Time for a fresh start.

Plenty of good resources here, if you were truly able to do this: “So I took May to focus on me. I deleted all social media, and focused on my happiness. I had no contact with Mark.”

You were happy without Mark. And people who have the ability and strength to look to their own happiness instead of expecting it as a reward or a right from others are going to be more attractive anyway than people who are needy and demanding. Funny how that works.

Sounds like you’re that kind of person…and Mark isn’t.

I would move on with other people. Not necessarily to date, but to hang out with. You might meet someone who is a better fit with you. Mark doesn’t sound like he is.

I believe that you did the right thing for that situation.
It looks like Mark want you to feel what he felt and that spells revengeful person.
He has shown immaturity and cruelty as he knew what it felt like yet he wanted you to hurt too?
A truly loving person would leave without hurting the one that they supposedly loved?
Perhaps it is a conquest fight between him and the other male…something he must grow out of or he will continue in other relationships too. You are not owed to him anything except truthful feelings and honesty. You are right to leave people that are not ready to accept that everyone has to love him. Some are trying to make up for a loss in childhood of a parents love and thus reflect it in relationships hoping to obtain the from present relationships. He will continue until he finally gets therapy to realize that he in fact is valued and loved and that it was his parents problem of not expressing their love for him not his fault.