He seems to think he can come and go and messes with you and your feelings. This would be really goof for you to try I know it will be painful but it will help and would not hurt to try but it has to be longer then a day maybe do this for a good 1 week or 2-3 weeks and don't give into him at all or call him or answer his msgs or texts or call don't see him or anything cut everything off completely . don't ask him to go over . this is something i suggest you try but you have to do it all without any contact and no in person seeing each other nothing. Ignore him . it will help.