If you want him to know that you are serious, be serious. Leave him.

He is becoming abusive. This is how abusive people act. They start by charming you and becoming a huge part of your life. Then they slowly start to isolate you. Then they begin to convince you that they know things about you that are embarrassing or things that could be used against you. Then the full on abuse starts. He has manipulated you into a pattern and you are indeed in a dangerous place. Thank Goodness he has not become physically aggressive!

His problems are not your fault. They are HIS issues. They are not yours to fix, nor are they yours to tolerate. You do not belong with him. Nobody who genuinely cares for you would say those things or use past incidents against you. Get out of there fast! And do not return.