I’m shallow

I think my boyfriend is unattractive. I’ve been ignoring it for so long because I didn’t want to seem shallow and I wanted to look beyond the physical body to the beautiful person he is inside but lately I’m repulsed by him and I feel so ashamed to say it. His facial features are just not appealing to the eye and I sometimes try to pretend its attractive but it’s not. And I keep looking at hot guys and imagining myself with them. I know I’m such a bitch but if I marry him it’s only going to get worse isn’t it? I’m so attached to him tho every time I get close to breaking up with him I cold chills and super scared. Im so lost