Choosing courses :s

I've already chosen something, but I'm not sure at all about this

Omg this is pain !! I'm trying to choose my courses for the next 3 years in Kathedral school and it's not so easy, it's freaking hard. I don't get anything. What courses would be good for me or what do I want to do after those 3 years. I don't know what I would like to work with when I've finished school :o And these courses have to be chosen until friday...omg. I hate this.
I have already chosen some courses, not all of them, but I will probably change it like 100 of times before friday.