Stuggling to get over a break up

My boyfriend of 7 years cheated on me with his best friends sister , and is telling her he wants to be with her. But still trying to sleep with me and cuddle me.

Basically he lives with me because his parents gave his bedroom to his over brother so if I kick him out he has no where to go. I’ve given him a month to move out.

He won’t admit it or make up for what he did.

I want to get over him but it’s really hard. I have no friends to go and see to make me happy. Nothing