Fear of the Future

I am in a semi-new relationship. (Under 1 year)

Before this relationship, I was in a 4 year very serious relationship that ended pretty traumatically for me. He ended up sleeping with another woman, which I didn't find out about until after he moved out, while his stuff was still in my house. I was completely blindsided by him leaving and completely devastated.

I have been very honest with my current boyfriend about my healing process and the fact that after all that I have been through, I am pretty unsure of what I am wanting, and am still trying to figure that out. He assures me that he is okay with that and he just enjoys spending time together.

I still can't help but have some anxiety about my relationship and about the future of it. I REALLY care about my boyfriend, and I want things to continue how they are, but sometimes when I think about him asking me to move in with him or him possibly asking me to marry him someday, it makes me anxious because lets be honest, the last time it didn't end very well for me. I am scared. This is also the first relationship that I have been in with someone that has children. I don't have any of my own, but I do work in the education field. It is something completely different for me that I have never done before and being in a "parenting" role is a bit out of my comfort zone at the moment. I know that it will take time for me to get used to things and become more confident, but I worry "what if I don't feel more confident about this?" I find myself constantly thinking "what if" about the future and it is completely overwhelming me and making me miserable. My boyfriend is so supportive of me and my feelings and is not pressuring me in the slightest. My anxiety is what is putting all of this pressure on me. "What if I never feel like I want to move in with him?" "What if he asks me to marry him and I don't want to?" "What if we break up?" "What if I'm not good with his kids?" I'm so exhausted thinking like this and being anxious all the time but I don't know how to make it stop!