Wow, I'm really sorry that you only get sleep every few days... that sounds so hard! I can't say I've struggled with this much, but here are some things that I know of that might help:
-When you go to bed, try the "zip up" method. Zip up an imaginary "pouch" around yourself, to block out all other energies
-Meditation (as Sandie suggested)
-Don't eat anything before bed, especially not anything sugary or high in protein
-Don't use technology for at least 30 minutes before trying to fall asleep
-Keep your work space separate from where you sleep
-Try progressive relaxation and visualization techniques (you can find these online)
-Sometimes when I can't sleep I try to "watch" a movie in my mind, and remember as much of it as I can This usually makes me tired, keeps me entertained, and distracts me really well from stress and negative energy
-Make sure you're the right temperature; our body temperatures naturally need to drop a little when we fall asleep, so if your bed is really warm, that might be a problem..
-Determine the things that are most on your mind, the things that bother you the most, and make a list of them. Then make plans for what you can do to make them better, and then when they come into your mind as you're trying to sleep, tell yourself that you "have them covered" (that you already have plans for what to do)
-Write in a journal or read a book before bed. Semi-boring books work especially well
-Take a warm bath or shower before bed to relax your muscles
-You could also try prayer. As odd as it sounds, this is one of my favorites! It helps me so much..
Anyway, I hope these might help a little. They probably won't work right away, but maybe they can help you get a healthy sleep routine going again. Best of luck!