Literally help

I just argued with my mother about school and stuff. She told me since i got a phone, my grades have dropped(which is not true) and my personality changed to worse. Anyways, after arguing for about 15 minutes, she just told me that i'm worthless, useless and that no one cares about me. I always felt like i wasn't enough for her, but now i realised it's true. I have had 2 mental breakdowns till now and i don't know what to do... I want to talk to my friend about this but i don't know how they will react... what should i do?