No sexual attraction

Is it weird that I don't want or feel the need to have sex with my boyfriend ? For some reason, I suddenly stopped.. wanting him. I guess you can say. Idk what to do ! I'm not sure if it's me or.. I'm not sure. But ever since I kinda got drunk and slept with a women.. I don't sexually want him and i think it's because I feel guilty.. but I have told him I cheated but he didn't really mind.. advice ?