Getting back with the ex?

My ex and I were friends for a year and then dated for a year during our senior year of high school. He broke up with me. Then 6 months later contacted me. Then 2 months later broke it off again (it was during the Corona so we never hung out). And it has been another 6 months or so. We got along great and the break up was kind of out of the blue.

He is in a relationship now and just told a mutual friend of ours that he is not happy and really misses me (obviously I was not supposed to be told this.) But he feels bad about contacting me again after the second time. While we dated we never had sex or anything and from rumors I am pretty confident he is intimate with the girl he is with. Our mutual friend asked if that would be a problem and he said he does not care about that. I just started going on a few dates with a guy and now I feel so confused. I never thought this would be an issue. Am I not ready to date or should I keep moving on?

Guys I feel crazy! Please give me some advice!