How do i overcome dependency on cheating ex?

Tldr; ex cheated on me and we broke up, tried to fix things but he didn’t want to. We still hang out, sleep together etc and I find myself absolutely hating life when he’s not around/talking to me. Please help!!

My ex and I (both 26 M and F) were together over 2 years and broke up about 2 months ago. He was, and still is my best friend.

He emotionally cheated, and I honestly wish I could hate the guy and tell him to eff off out of my life, but I honestly love this stupid moron to death and can’t imagine a life where he is not in it.

Initially we were going to try and sort things out between us and date slowly and just see where things went, but complications with family and his feeling of not being himself made him sort of decide that it wasn’t the best course of action.

We went no contact, after my family had asked him to block me on social media as they didn’t trust me not to contact him. This lasted a week before I had to go and text him and we struck up conversations again.

However I find myself almost “addicted” to him. I’m not happy unless I’m with him, or texting him. If he takes a while to get back I start getting so stupidly sad and anxious. If he doesn’t want to see me, I feel even worse.

We met up this weekend, stayed in a hotel and it was honestly just like being a couple again. We mostly had a really great time.

Then someone was trying to ring him and ask him to meet up and they were saved under the letter “G”, and I then just felt awful. Thought it was his ex (her name starts with a G and he had recently been in touch after our breakout) and got all upset, even though I technically have no right to feel this way as we are not together.

The moment passed and we had a nice day, he came back here for a little while and fell asleep on me and I was in such a happy little bubble. But then my curiosity got the better of me and I tried to access his phone, but he’s changed his passcode.

I thought I’d gotten away with it but he soon realised. He wasn’t mad at me, but I was very upset. Then he had to go home because he’s going away on holiday tomorrow and I just started uncontrollably crying. He said I need to work on myself and find things that I enjoy that don’t revolve around him.

I hate how I have this dependency on him, I really can’t be happy unless he is involved and I know that’s not healthy. I even know that we probably won’t get back together but I just cannot help it.

How do I stop being such an idiot and dependent on him??