I've been having a lot of drama with school lately...?

Okay so here's the long version:

I'm pretty sure this all started when I lost my faith in religion. Without God, there's no afterlife. Without an afterlife, then what's the point? I'm not going to be happy forever. So, I started getting my mind off the subject and started playing video games more frequently. I feel like losing my interest in my academics, but I know that if I don't get a college education, I'm not getting a job, and my life's just going to go downhill from there. So, I tell myself to try, and can imagine myself doing it, but I can't make the reality happen. When I fail, I let my emotions take control of me and go through a short period of rage/grief.

I think the main problem is that school isn't flexible. I dont control the pace of the entire class. I dont control the intensity of work. And this starts to bother me. A lot. This is where my drama comes from. 5 Honors classes, and a crap-load of stress. I feel like telling my mom that I need therapy and that I need to attend an online high school so I can have a more flexible learning process. However, I don't know when to tell her/when an appropriate time is. I've missed a week of school since I got sick and now I have an essay, an algebra 2 project, and a bunch of homework due. If I tell her now, I feel like she's going to deny my request. What should I do?