I think I messed things up

No.

Pretending nothing is/was wrong is lying. That's not how mature relationships develop.

It is time to accept this as a learning situation and do better the next time you're getting to know someone with an eye to dating/a potential relationship.

It sounds like he didn't understand 1) how attached he still is/was to his ex, 2) how invested you were in him.

You didn't tell him what was wrong when he focused on his ex.

You'll both get better at this (but likely not with each other).

Great advice from @tibbleinparadise.

You can't complain about the quality of advice from strangers on the internet. If you are so aware of what happened, why ask us what to do?

The situation has played out. You, this guy, his ex, it happened. Maybe there were miscommunications, misunderstandings, who knows. All we know is what you've told us and, of course, our interpretation based on our own experiences. My life experience tells me that you guys weren't on the same page and this guy wasn't quite over his ex. It's okay. Learn and move on.

This statement right here should be repeated in your head over and over until you realize you are better off moving on. Why waste feeling like crap over this?

I think you should talk to him first, maybe there is something wrong you did you havn't reconize..

I talked to him, I was basically right. He was still into his ex and rather be with them over me. Whatever we had is over now.

Yeah, no reason to be around his ex! Comparisons come too naturally!

I see, did you decide what to do ?

What's happening now? Any better?