These ain’t excuses

Someone tell me right now how to end a relationship with someone who refuses to be done. It’s all there crystal clear in front of this mfers face but he refuses to believe me and understand it’s over. We share a 3 month old baby. But we don’t get along. He’s saying he threw away deadbeats and drug addicts for me but yet buys me an engagement ring. How tf can I end it with him, I want it to be civil because of our son. He’s making me feel trapped and I don’t want to be. I’m sure your thinking I’m making excuses but it’s not. This is life for me. So please how can I get this dude to understand 100% that it’s over. I do not want to be with someone who dies drugs. Point blank. It’s done.