Ditch her and run away from home.

My mother is about to kill me because she has anger issues

Tell her to stop acting crazy and to get a grip, that will make her think rationally and calm down for sure.

How should I sneak back into my house after drinking a little too much?

Break a window, walk into your house as loudly as you can, and try to break the maximum amount of objects. If that doesn’t work, call your housemates and scream and slur at them

I want to sleep but I’m in class

Go to the nurse's office and tell them you have a headache. They'll let you lay down, and you can utilize the chance to take a 20-30 minute snooze. (based on a true story of my days in middle school...)

I have an exam in the morning and I didn't study, what I do to prepare on short notice?

Don't, just cheat tomorrow. Make sure you tell your teacher about it though. It's okay to cheat as long as you tell the teacher afterward. 

I should go to bed, but I want to watch Gossip Girl right now. What do I do?

Take the TV with you (or your laptop or whatever you're watching Gossip Girl on) and go to bed. Multitasking! Let the episode play while you are asleep for best effect. Maybe it will find its way into your dreams. 

I am very, very shy. 

Collapse the Slytherin Dorms

I want to fly.

Flap your arms with a bird. 

A evil teacher refuses to give me Os! 

Inform the teacher of how they are unauthorized to judge your work, as obviously it is you who are the more educated on the subject. They will be grateful that you relieved them of their obliviousness and you'll have an O in no time!

My friends are making fun of me because of my boater hat.

My first idea was: Burn your boater hat. But what if you're really, really fond of it? Silly idea. No, burn your friends!!

I am living now in an irrational fear of being expelled because I told a teacher he was unauthorized.