I know how you feel.
I dropped my calc class halfway through this semester and wasn't doing too hot in my other classes, all being science. Studied non stop all last week for my finals which were this week and did pretty well on them I think.
It could also be a sign that you aren't in the right major. I'm completely ditching science next year and going for a dual major in film and communications. Not the best job job outlook, but I know I'll be happy doing what I'm doing. I plan on going to graduate school for business, probably marketing, so i'll see where that take's me.