I'm a student in an IIT.My grades have been falling in recent times-I'm trying my best,putting in 20 hour days,reading every thing I can-But it's just not enough.My profs are looking down upon me,I cannot tell my parents-They'll be worried,I feel like giving up on everything.Can anyone please help me?What should I do?I'm going crazy here.

I had similar trouble whilst attending university several years back. Sounds as though your trying to put too much effort, it can easily affect your work if your tired and stressed out. You need to find some way of outputting your stress, like taking up a sport or general pastime. In my case I took up jogging and it helped a lot.

Too many hours, not enough sleep, not enough other activity.
Your parents are there to care and help, so don't wait to tell them another minute. If they get overly anxious, back away. You tried.
Any professor who looks down on a student who is trying shouldn't be teaching. One might, but all of them? Are you sure you aren't looking down on yourself instead? How have you approached talking with them?
What if this type of training/learning isn't for you? What if you are an artist or musician or dancer, or mechanic or animal trainer or bookkeeper?
I had a full scholarship to one of the best schools in the world and dropped out before I flunked out.
Take some time to examine what it is you really want to be doing at this time in your life.