Love problems

!This is my first thread so sorry if it's a little confusing!

I'll just begin now.

I've been in a realationship last year and I thought I've gotten over the person I've dated. We became good friends again but I always had a feeling that there was still more than just friendship because we just broke up because we were both too young to know what to do for a realationship to last. So we're still on good terms.

About two weeks ago I've started texting somebody new and we were getting along pretty well. They asked me out two days ago and so we went to our cities cinema to watch a movie. First everything was going really great. But I think at this point it's clear that there will be a problem. Well after we kissed which also was my very first kiss because all my realationships before were well... let's say awkward. I was to afraid to kiss someone of them.

So after that kiss I started to feel weird. Something in me told me that this isn't what I want. They aren't the one. As the hours passed I realised I still have feelings for my last ex. I feel so bad about this because this new person keeps telling me that I'm the perfect one for them. They care so much about me but I just can't feel anything for them. I also feel disgusting after that kiss and everything else.

Now I really don't know what to do in that situation. I can't stay with them because I would feel uncomfortable with the fact that I don't like them in that way. But I also don't want to hurt them. In addition I also noticed that this "friendship" between me and my ex isn't platonical at all. They kept giving me signs and now that I'm in that new realationship they kinda keep a distance between us. I'm not good at telling if someone likes me but I think my ex still likes me too.

Could anyone give me advice? I could really need it since I have no one else to talk to.