Ladies, how would you react and am I over thinking this?

Ok so here is my situation, at the beginning of the relationship my boyfriend would always try to meet up with me any time he could and and was always free to talk or hang out which was great. I'm a pretty understanding person I think so it didnt bother me when he said he was busy all the time. Recently however he has just kind of stopped meeting me and I have tried to be relaxed about it and think that maybe he just is getting caught up in other stuff right? Well that has just kind of progressed in to him never having any time anymore ok but when I was out at lunch when he should have been in class I found out that he was skipping his class to hangout/talk to another girl. Not just any girl either, but his ex girlfriend and when I saw him he just looked at me and continued talking to her... So he doesnt have time to meet me for a bit but he can skip class to talk to her? Now am I in the wrong for being concerned and slightly upset?

UPDATE

So the first thing he messaged me today was look we need to talk

so yeah its definitely over because he can't handle a relationship right now... and yeah thats it I guess. Thank you so much to everyone who commented