I think I'm gay

I have a boyfriend and I feel so bad, hes been nothing but loving and supportive the entire time we've been together and I really don't want to hurt him but I've figured out that I'm probably a lesbian.

Turns out it's really hard to figure that sexual confusion shit out when you have a boyfriend.

I feel terrible and I know it isn't in my control but we're basically that perfect storybook high school sweethearts couple, everyone says we're perfect together.

It's just, like if he were the opposite gender...

I'd want to be friends with him still if we did break up but I'm scared of hurting him and he told me he was really depressed before we got together.

Should I break up with him, and how do I do it if so? I'm really scared.