Your posts are so sad, I’m so sorry you’re going through this. Standing back, it seems clear to me. Stop doing the running. Distract yourself, as much as that is possible (I understand how easy that is to say, but not to do).
You have to find out now if he is genuinely interested and the only way you can do that is to step back and see if he steps up. If he doesn’t, it’s very painful, but at least you will know.
Much easier, in some ways, if he would definitively leave you and it’s tempting to suggest you should leave him so you can move on. But it’s not absolutely impossible that if you make yourself more absent, that he will realise you are important to him.
Entirely different situation, but a friend of mine in a long term relationship told me that her partner once told her he had met someone else and didn’t know if he wanted to stay or leave. I probably would have tried desperately to hold onto him, running around making efforts to do nice things, waiting in agony to see what decision he made (Mumsnet calls it “the pick me dance”). She didn’t. She told him to leave right now and go. He did. Within two days, he came crawling back. They’ve now been married for years and seem very happy.
But I was impressed by her strong boundaries. She loved him, but she was not going to let anyone mess her about or mess with her head. I haven’t read the book that Merry recommends, but I have spent a lot of time reading this board. There are a lot of clearheaded women here and I have learned a lot. If someone is treating you badly (which he is) you need to set yourself some boundaries. Know that there are certain situations where you have decided that you will walk away, no matter how tough it feels. Because if you stay in a relationship where you feel you are not being treated well, it will never be a happy relationship. And an unhappy relationship is not one you should bring children into (assuming that’s something you want).
As an aside, I had a good career before I met my ex. It didn’t remotely cross my mind that I could have children as a single women. I was looking for the perfect family life, and was worried I’d never find it, so I settled. Don’t make the same mistake. With hindsight, I wish I had thought around other ways I could have had a family without having to commit to a man who wasn’t right for me. You haven’t mentioned children, so that may not be important to you, but you mentioned your age, so it might be relevant. If children are important to you, you don’t necessarily need a man.