Why do I feel guilty?...

So I am 22 years old, married, and just had my first baby a few weeks ago. My mother and I have NEVER had a good relationship. My parents separated when I was in first grade and when we moved out away from my dad, its like my mom just stopped caring about me and my 2 younger sisters. She started dating men, choosing them over us. She got married a couple times to men who beat her and did/sold drugs. She belittled me and my sisters. We lived that way for years. When I was 14, I started dating my now husband, so he has been with me through a lot of this. When I was 16, I found drugs in my moms closet (meth). I was shocked. I kept checking the baggie every few days and I started noticing a little would be gone at a time. I called DHS on my mom (anonymously) we went through the family court, she failed the drug test and we got sent to live with my dad in Another state. She straightened up, did what DHS said and my 2 sisters went back to live with her. I stayed with my dad (I was in 11th grade and finished). For my senior year I moved back to my home state and lived in my dads house by myself. My dad works all over and would come home for a couple weeks then have to leave. Anyways I graduated, went to college and graduated, I am a nurse. My mom is narcissistic and is still doing drugs. She claims she isn’t but she looks AWFUL, doesn’t work, lives with my uncle, has crazy delusions. For example, my youngest sister went to stay the night with her the other night. While she was there, my mom was freaking out and turned all the lights off and tv off and was making my sister be quiet and telling her that someone was coming with machine guns to kill them and that they were gonna chop my sisters head off and all kinds of crazy stuff. She hates my husband, he has never done anything to her except stick up for me. He does not treat me wrong, we have a good marriage. Any other mother would be happy for her daughter. Instead, my mom asks my sister how much money I make at my job so if he ever leaves me, would I be able to take care of myself and my baby. WHO SAYS THAT?? Anyways my mom just called my sister and told her to ask me if she can come see the baby. (He is 3 weeks old and she has not seen him or asked me about how he or I have been doing. She has seen pics of him and asks my sisters about him) I told my sister to tell her that I told her 6 months ago that if she wanted to see him to leave her bf/drug dealer alone, get off drugs, and go to rehab. She told my sister she can’t go to rehab cause she doesn’t have money. And I said well she could have left him alone and got off drugs. And she started crying and saying that she doesn’t do drugs and she “doesn’t mess with him like that” and saying she guesses she’ll never get to see him. I just really don’t understand why it’s so hard for her to get her life together and want to be a better person to be in mine life and his life. And I know I’m not in the wrong for telling her no but for some reason I feel so guilty that she is upset and like it’s my fault or something. Am I in the wrong? Why do I feel guilty? I’ve tried getting her help but she just denies that she does drugs when it’s obvious she does. She has said and done so much horrible things to me but I’m willing to put it to the side if she gets her drug issue under control but all she does is deny it....I know this is long so if you read all of this, thank you. I just needed to vent and would like advice if you have any.