In love with me but went back to his?

So recently I got in a relationship with a guy I have been in love with for the last 4 years. He left his fiance of 3 years to be with me, he told me I was the one, he was in love with me, and wanted me to get pregnant. I honestly felt like I was finally about to get my happy ending.

Things were going really well, we spent a lot of time together, and he went out with his friends. Something he said his ex would never let him do, but I am not that type of person that wants to know where my partner is 24/7.

Anyway, one morning we woke up and everything seemed to be different, I could not put my finger on it, but I decided to arrange to go out with some friends as I had arranged to go out with colleagues in the evening. He was barely talking to me so I decided to ask if he was having second thoughts. To which he replied he felt like he had rushed into being in a relationship after ending his 3 year relationship, I completely got this and told him just to be happy and that I was here if he needed anything. A few days later I receive a message saying that him and his ex were trying to sort things out.

I am completely confused by the whole situation. He told me how unhappy she makes him, how he has no life as she controls him, and how he has just been miserable.

Do I wait for him again? Do I move on?

Please can somebody advise me as I literally feel so heartbroken right now