Advice ? Maybe?

I’m new to this whole dating thing after a divorce and kids.... with that being said, I crossed paths again with a man who we used to have a fling for but went our separate ways which both resulted in marriage and divorce... the woman he married did him wrong she was very toxic, abusive, took everything from him and cheated on him. They didn’t have kids together but she had kids from 2 prior marriages.... anyways, to the point.... we’ve been dating a little over a year now, we went on a mini vacation this weekend and it ultimately got ruined by him receiving a message that his ex got remarried. I saw his heart drop, I saw it in his face pain and hurt.... and that hurt me, it hurt me because I’ve assumed the reason we won’t essentially become official is because he was still in love with her and that proved it... I expressed my feelings and it pissed him off... so now he’s been distant and down because he says he looks like a fool fit assuming she was cheating when he knew etc.... will it be possible for us to even be together if he’s not going to let her go? Should I just run now before more heart break?? I’m just lost? He says his biggest fear is being left, yet I feel so pushed away by knowing I’m giving my all for him to still love her. (Side note, they’ve been divorced 3 years now) I guess I just need guidance, Is this normal? Ughhh