[She.Smiles]

Hello There. I have totally been there. Sometimes you just need to sit down. Maybe put on some music or the television actually. I can do homework sitting in front of the tv because I will stay sitting there, and work on it. If you don't understand you could get a tutor or look it up online, I used yahoo answers to get my math explained to me quite a bit actually.
If it's where you understand the work, just can't sit down to do it; Try what I said above, or go to the public library. It's about discipline. Set yourself down and do not get up until the work is done. Failing a class is not fun. I had to take summer school, and I am still making up the other class that I failed because I did not try hard enough.
Hope you can get on track, and good luck.