Your story resonated with me as well. My mother was and alcoholic and my father a prescription drug addict.
I also grew up with extremely low self esteem, inferiority issues and social anxiety as a kid and teen. Unfortunately I turned to drugs and alcohol to self treat my problems. I'm really happy that you haven't chosen that path for yourself.
I'm going to echo some others comments on here and tell you that you are not responsible for your mothers actions! You can save yourself! You absolutely deserve to love yourself enough to seek whatever help you think you need to heal these wounds!
xx all the best to you and thanks for sharing your story.