Idk if im right or wrong abt this

Ok so me and my ex gf were separated for one year and then 1 year before we started talking again but were not together. And then after some months she posts a story with a guy, where he gives he a back hug. After that i decided not to talk tonher anymore and we should nit be together, cuz she did not told me abt him. She told me, that she didn't wanted to be with him anymore and she is going to break up w him but that was not what i wanted to hear. I wanted her to apologize and realize she made a mistake but all she did was telling me excuses as in her "apology" and making me feel guilty fir getting mad at her. Now, even tho i love her so much we are not together. So my question is that is it right what i did or not? Did i overreacted or not?