You probably have an eating disorder, sorry to break it to you, but 7 hours of exercising is...unnatural. Thinking that eating under 900 calories a day is a great thing is also bad, you CAN lose 30 pounds without doing this. I also just want to mention that its a proven fact that people who try to lose weight extremely fast have a very low chance of succeeding and a lot will end up gaining more weight back. So just stay calm, see a doctor, you can lose weight the healthy way. :D