About to leave my boyfriend of 6 years help

I just feel like I have no more fight in me to deal with the drama or the lies so I'm finally going to tell him I'm done and I can't sit here and not get the love and affection I use to get... I think he's seeing his ex that he got pregnant when I was pregnant and her friends keep sending me thing telling me he's over there having sex with her and telling her that there going to get married I'm just over it I wish I could move on I don't know how to tell him to leave and mean it when I really want him here but I can't take it no more