How do I get rid of my low self esteem

I’m 15 and I’ve been living with my grandparents for nearly 2 years after I stopped going to school due to depressive behaviour.
2 years ago, I lived with my mother whom I have an up and down relationship with and my younger sister.
My mother and I have always fought and argued a lot, she’s a stubborn and selfish person who believes she can do no wrong, and for all my life has pushed the blame of many events that have happened onto my father, who I do not see often at the moment as he has another family. My mother constantly blamed and ridiculed him infront of me, though he was not such a saint either, my mother made him out to be Satan and often called me Satan’s daughter because of it. I was also blamed for many unfair things in which it would not have been my fault. It was damaging in my childhood, not only because I grew up with a quite absent father, but because I grew up with a selfish and emotionally neglecting mother. I have been going to countless numbers of therapists and psychologists since I was 8 or so due to being a violent child at home, and finally when I was 13 I ended up being what I’d call, depressed. I developed severe anxiety issues to the point where I would get anxious to go into school, and around this time is the point where I truly felt like I was nothing. I thought and honestly believed that my presence was not noticed and that if I stopped going to school then no one would blink an eye or care at all. I had friends, quite a lot, I had friends who were sort of the bad bunch and did drugs, who I hung out with most days out of school (although most of the time i was the odd one out, who watched while they did the bad stuff), I had friends who were mean but I still hung out with them at school, and then I had friends who were nice but I didn’t know very well. I wasn’t necessarily lonely ar school, but I still felt as if I wasn’t there. And slowly but surely, my self esteem and self worth and value dropped, and I genuinely thought there was no point to me being alive. I went to the school therapist I had been seeing and I told her I felt like I wanted to die and I ended up getting pulled out of school and sent to my grandparents to live. Eventually I got a chance to continue going to school, and I went for one day, but I left early and never went back. Instead I got put into online school and for the entirety of last year, I did nothing except sleep, do occasional online classes and waste my time. I started going to school again this year, which definitely improved things, but recently, I’ve begun to feel depressed again and I feel my self worth going down. Throughout my life I haven’t been given much time thought or effort from my parents or anyone around me, so although I feel this happening and I know the reasons for it, I still can’t seem to stop feeling this way. I wish somebody would just come into my life and fix me, even after my attempt this past year to fix myself, it all just seems to be for naught. I’ve had countless stresses this year, from friends, to my mother getting into an abusive relationship and having to live with me and my grandparents for a while, and then having another child. It all feels like too much for me, but I just keep it inside, and don’t think about it too much. I feel like if I just improve my self esteem and self worth I’ll feel like living again, because I know that no one is going to randomly appear and fix everything for me.
If anyone has been in a similar situation as me, or has had the same never ending deep rooted feeling as me can you please give some tips as to what I should do?
Thanks