I'm upset about my ex-boyfriend staying over with a female friend
Why are you worried about what you ex is doing?
Because I still have feelings for him
You shouldn't expect your ex to stay faithful to you if they aren't with you anymore. You should instead move on and date other people too.
I want to get him and make him my loving bf.
I think that you should just try to move on from him. It is not fair to expect him not to try to move on with his life as well.