Bad situation

Hello, my background info is a have a toxic relative, ill call them A, who i spent a lot of my childhood with. This person is also abusive to my father, ill call him B, however he does not stand up with them and even sides with bc they are his sister. I recently had a really great relationship with a someone, Ill call him C, who i was very vunerable with. Overall i am not close with my relatives I only stay in touch with B because I care. Anyway I had this new relationship i was really excited about. And i decided to move abroad with C. Anyway toxic relative A decided to find us on social media (which i now do not have them near me on social media now) and toxic relative A kept trying to contact my relationship C over and over again bc I wasnt talking to A. Anyway this damaged greatly my relationship with C. I grew up with a lot of critisism and a abuse from A with A always turning people against me and a lot of emotion abuse. Toxic relative A also abuses B but with this situation B is not supporting me bc B always sides with toxic family. I also has my partner not listening to me not understand the abuse and trauma I received from toxic relative A. After them continusously messaging him he keep trying to reply to them behind my back. And was telling me I have to write back and fix the situation with toxic relative A. Now my relationship which I prorotised with C is damaged I not longer trust him bc he didnt see or understand that i dobt want to speak with A. And also my relationship with B is now also damaged bc i tried to get support from B and was given no support. And there still close relative of A. But B is not directly close with A as they do jot speak. But noone in this family stands up to A or calls out the bad behaviour of A.

Now i feel all alone i dont trust C or B and now i am dont jnow how to get past all of this