It sounds like a rotten situation to be in, I'm sorry that you are going through this! And yes, if things have already been bad and he is now taking your meds, it's probably best if you ask him to leave; that is what I'd do. I'll be keeping you in my thoughts, and I agree that you need to do whatever is best for you.
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From the movie The Hours: "If I were thinking clearly, Leonard, I would tell you that I wrestle alone in the dark, in the deep dark, and that only I can know. Only I can understand my condition. You live with the threat, you tell me you live with the threat of my extinction. Leonard, I live with it too."