The first step is that you've acknowledged that the GED path is not for you.

What's your online recovery like? I mean, is there an interactive interface with live teachers and students?

Your parents could possibly be angry because fear comes out as anger.

Have they set you up with a counselor? Is speaking with a counselor even something that would interest you?

I have a friend who told me that it's standard knowledge and proven fact that it's more to do with the developmental stage of your age, as my own son has struggled himself this year. That whole "pointless" piece of your OP speaks volumes to everything that he, himself is going through. Imagine that, you are not alone!?!

One step, at a time. Do you have hobbies that you enjoy? Do you have friends that you spend time with?

I spoke to another colleague that runs a night program and she said there is actually a waiting list. Says volumes about how not alone you are in this struggle.