I am very sorry that you are hurting. I think he’s been sincere the whole time about it not being a serious relationship.

He was pretty vocal about it. He also doesn’t ever say he’s exclusive so he was possibly not exclusive either.

I doubt he used you for sex because it only happened two times in several months. People who use others for sex would certainly want it more often than twice in the whole duration of dating

He wasn’t very affectionate because he either just not an affectionate person or he was just not really feeling it.

I’d say 2 weeks long trips with friends would be questionable if you were married, engaged or in a long term committed relationship. But after only 4 months of dating I’d say it’s perfectly fine. If one is going to cheat, they will no matter where they are.

Calling and texting a lot isn’t an Indication of anything. It could mean he enjoyed your company but is not necessarily an indication of serous commitment

I think sadly what you wanted out of this relationship and what was really happening wasn’t the same thing.

It happens to many of us. Especially when you are young and are just starting your romantic experiences. People usually reveal themselves early on. We just have to pay attention. What you see is what you get. If someone tells you that you aren’t his girlfriend and you two aren’t in a relationship, then you either accept that this is a casual not serious non committed encounter (if it’s ok with you), or you go on looking for more suitable partner.