Motivation advice??

I really need some advice rn, i lost all motivation to study since like 3 years and i really want to change. For background, my teacher always used to tell me that i will never succeed in life no matter what i do, so i guess after a while i started believing him and didn't find a reason to keep studying..but now i started a new school and i still struggle with studying a lot. I haven't picked up a textbook or even did my homework in years and i don't know where to start again. I feel like i should set a goal that would keep me going, but i can't think of anything. Anyone in the same situation??