Unwanted roommate

My ex boyfriend and are living together and I HATE IT but he won't leave!!! We broke up while living together and trust me when I say we're taking the break two totally different ways. He's already talking to other girls going out with other girls even spending nights with them!! Me? I'm devastated he is my first EVERYTHING.. He's all I know... But he won't leave me to deal with this breakup.. Literally My heart is broken!!! He tells me to just let him be and he'll get back with me eventually.. He has even said if I get pregnant he would be with me sooner but i think that's his way of trying to have sex with me. He takes advantage of the fact I still love him but that changes nothing because after what he has put me thur these last 8yrs I know leaving him is the best thing for me But how do u grieve when the person is in ur face everyday hurting u still and refusing to let u be.. It's my house he's not on the lease he just want leave...