Whats wrong with me?!?

For about the last month I havent been able to sleep, some nights have been completely sleepless and I have felt so rough the next day, others I have fallen asleep at 3/4 o clock in the morning and woken up every half an hour. I havent had a full nights sleep in over a month now and im exhausted :( I have good sleep hygiene, dont spend anytime in my room unless im sleeping, turn off anything electrical a couple of hours before bed and read a book, dont do any physical exercise directly before bed but earlier on in the day. I dont drink caffinated drinks.... what else can i do?! its driving me mad, makes me feel very down and hopeless during the day, most days are just a sad, low haze and i hate it, please help?