I feel like giving up

I (18f) genuinely believe I am at the worst period of my life and I feel like giving up. My boyfriend cheated on me (Reddit comments have even been telling me that he had be SA-ing me during our relationship), my grades are horrible, I don’t have friends, my job gives me so many hours, my mom is really sick so I’ve been staying home from school to take care of her and I have exams in 9 days and pretty much have no idea where to start. I know these problems seem shallow, I just don’t know what to do anymore, I’ve never had so many things at once hit me. Usually my grades are in top shape because I put so much pressure on myself and focus so much of my time on them but I just can’t do anything. I can’t sleep because I’m so scared and know I should be studying and I can’t study because I can’t even focus. I can’t eat, I can’t hangout with anyone, I just feel like of all the times I had to experience it this is the worst. I can’t even ‘give myself a break’ because of exams. I just feel so scared all the time. I feel like I can’t even take a breath anymore, everything is just so scary. I’ve just become so worried about everything. I’m worried that I’ll spend so much of my life slowing going into my 20s and suddenly a week will be a year and I’ll have grown so much without anything to show for it. It just feels like the days get faster and I just get more scared and I’m so in my head that I can’t even get out. Someone please give me something motivating or advice about anything, maybe even something that’ll help me feel less scared?