I am twenty five years old, I find it very difficult to sleep even for 4-5 hours in a day. My sleep cycles are irregular. Sometimes I feel sleepy at 10 in the night and for next 2 days I do not sleep at all. My sleep cycles keep on changing every 2-3 days. What should I do to get a sound sleep of 6-7 hours atleast everyday. As of now I am not suffering from any health problems.