Boyfriend?

Novah
I've been with my bf for almost 4 months now. He always tells me he loves and I think he truly does. But I feel so guilty bc I miss my ex so much. I tell my bf I love him too but I just feel bad. Idk what to do but I can't leave him bc I have feelings for him but idk. And he hates when I talk about boys or anything so I feel like I can't tell him this. Anyone relate?