I can never sleep because I'm always thinking?

I have a major problem with falling a sleep. I alway have something on my minde.. Like where did I put my gles or did I brush my teeth did I lock the door.. And i cant sleep if i dont do whats on my minde...I go through this every night. Then after I do whatever is on minde I start thinking.. About life and my family. I think about my dad who ped away a year a go most of the time.. I have never had this sleeping problem before my dad ped.. I also think alot about drugs because i take a lot if them like lsd... :/ On school nights I go to bed at like.. 3 sometimes 4 and have to get up a 6. And I'm only 14.. By the way srry for any typos I'm on my ipod