Am in the wrong?

So very long story short- my mother is a meth addict and as a result of her addiction she has put my sister and I through absolute hell. She's stolen so much from our family and done really awful things. She is still married to my father (he's in prison, not drug related and we have a good relationship,) and yet she's dating a guy who's 24. I'm 21 and pregnant with my first baby. She wants to come around but 1. As long as she isn't sober she isn't welcome and 2. Even if she is sober, I told her that as long as she's with him, I refuse to be around her. He's a drug addict that is in and out of jail, not to mention that she's 40 and dating someone so young. He's not mentally an adult, I mean, he does meth/heroin so what does that tell you. 😂 she makes me feel guilty for bringing him up and including him in the reason she isn't around. Am I in the wrong for not wanting her around even if she was sober because she's with him?