What's with me?!

Damn, I've been telling myself "I can't do it!" so many times in the past 2 weeks. The last 2 Comp Lab assignments, "I can't do it!". Tutorials for the 5 modules, "I can't do it!". Lectures, "I can't understand it!". Argh.. These are really driving me nuts.. Before long, my morale will be hitting a record low. What's worse, I spent so much time on the notes yet I still dont know how to do the assignment. What am I supposed to do? And I really hope I can start to tell myself again that "I can do it." soon..