Anybody else like this?

So I’m going on 5 yrs with my boyfriend, we have 2 kids together. I love him, he loves me, we’re doing well just arguing here and there but nothing serious. Before him I’ve had a lot of hearbreaks and awful relationships that despite all the years I still feel like they affect me. Because now I love my boyfriend but at the same time I feel like if he were to ever leave or cheat or whatever that I just wouldn’t care, id just leave and move on. It’s like I feel cold or heartless in a way