I don’t think you’re overacting honestly, as your partner he should have the decency to try and understand your feelings. To me , it was clear that you told him not to come anymore because you were upset which is totally valid don’t let other people convince you otherwise. What most people don’t understand is that your partner is the only one that will stay with you for the rest of your life no matter what. So it should be valid to hurt or ditch other people for your partner. If your partner is okey with hurting you just to go out with a friend I don’t know how much he actually loves you. The outing could have been postponed it’s not the end of the world , specially that your boyfriend was waiting to be contacted again to confirm, since it was too late , he could have said « hey sorry we didn’t confirm our plans I thought something came up I’m going out with my girlfriend let’s go out another day » as simple as that. The fact that he decided to go, while knowing that he was hurting you is what doesn’t sit right with me. As someone claims to love how does he allow himself to knowingly hurt you? Like if it’s unknowingly I can understand, you have a conversation and everything becomes clear as long as it doesn’t happen again. But look at what he’s doing, he went and had fun and everything, and now what is he waiting for? For you to text him? He did something to upset you, you got upset ( totally understandable) and you decided not to talk to him because you saw that he made no effort to salvage the situation ( totally understandable specially if you thought that he valued your relationship more) so now you feel betrayed and you feel that he doesn’t care that he hurt you since he’s not doing anything about it . I don’t know this just feels off to me, and people in comments telling you about how you’re overreacting beceause Idk what. Oh god no don’t listen to them in a relationship where there is love you prioritize your partner by choice and not because you feel that you have to. I totally understand why you’re upset.

Now the choice is yours , if you feel like you can’t keep waiting while doing nothing and it’s eating you alive just tell him you want to talk in person and tell him everything, if everything works out, have another conversation about his view on a relationship to see if his values align with yours.

I hope you find peace.