What am I doing with my life?!

I don't know what's wrong with me. This week I've skipped my classes on both monday and wednesday (today). I just can't seem to drag myself out of bed in the morning, no matter how important it is that I don't skip my hardest class (Virology). I almost didn't go to Bioinformatics yesterday either. Ugh. I feel like I'm going to fail and its like I don't even care. I just want out of school right now. I have no motivation to study. I don't really have any motivation to do anything. I just feel like being artistic and crafty again... I feel like painting pictures like I used to do. All I do now is hang out with my friends and get stoned. I've been putting that before schoolwork which I cannot do when I'm in 4th year honours. Frig I'm being an idiot but I don't know how to stop. I feel like I have way too much responsibility this year and I can't hack it. Mentally or physically. No one else understands how I'm feeling right now either... I just keep telling myself to make it through this semester and it will be ok. But really, even if I can make it through with just a pass, that means my GPA will drop and I won't graduate on Deans List, something I've worked SO very hard to get since my first year I fucked off like I am now (I had a 2.3). I've managed to get my cumulative GPA up to a 3.7 in these last 6 years....I can't lose it now but at the same time I don't care. Maybe I should drop Virology. I don't know. If I become part time I'm letting my lab prof down since I have to be full time all year to be TA. Being a TA is an awesome thing to have on my resume, but I can't handle school right now. Ohhhh I feel so stupid. These past few weeks I feel like crying every night. I really haven't done a thing productive. What am I doing with myself?!!! I've never felt this bad before. I don't want to be one of those fucked up girls. I'm too stressed out and I want to go back to bed...But I slept for 12 hours last night! I also have an extremely stressful day ahead of me -- I have to head up to school soon and go to TA consult hours and try to help students out with questions I don't know how to do because I'm an idiot...then I get to TA a busy open lab for 3 hours and try to help students out with labs I don't remember because I don't have enough motivation to study the years worth of labs before going.