I am unable to sleep without weed, what do I do?

Long story short I've been an insomniac since I was a child and have never slept well, this has caused me to try pretty much everything, sleeping pills, meditation, exercise, diet changes etc etc - the only thing that has had success is weed. However I've used this as a crutch for 5 years now and although I get to sleep its obviously not the quality of sleep I need and its affecting my mental state and energy levels (I am exhausted all day everyday).

Now I'm on day 4 without it, I have slept on average 1-2 hours a night, with the first night having no sleep. I allready excersise 6 days a week, have a healthy diet, full time job and plenty of hobbies to get my mind of weed so quitting isn't a problem its the sleep that's making me want to go back. Anyone have any ideas?