There is a great book called hope and help for your nerves by dr. clare weeks and if you are having severe anxiety around sleep issues, to the point of panic attacks, then you should look for this book. She helps with so many different types of anxiety and I highly recommend reading it.

I have had insomnia on and off for a very long time--so i know what you are going through. You can get some great relief from homeopathic treatments, which are all natural and have no side effects...I take calms forte by the hylands company the most--it really helps relieve the anxiety and allows your brain to calm down so you can sleep.
its also important to WAKE up every day at the same time no matter what time you fall asleep and its important to limit caffiene and sugar after 5pm--turn off the TV and computer and bright lights about an hour before bed--have some warm milk and read a quiet book in the dim light--make sure your room is cool and very dark..best of luck!