When I injured my IT before my first marathon, I had to take almost a month off from any sort of distance running. I swam mostly, and kept my runs very short.
The best thing I can say is, really listen to your body. Don't ignore the feedback that you IT is giving you. It's just not one of those injuries that you can ignore. Work on balance training, like one one of those balance balls, or a plank. Anything that you can do to strengthen your leg muscles is great. I like to practice some yoga moves that focus on stabilizing, and work out all my leg muscles.
I also know that everyone says Ice, but I was told to do ice for 15 minutes then heat just until you get that tingling sensation of feeling returning to the area, then ice again. I did this about three times in a row, every night. You just have to be careful with the heat though, so that you don't increase the inflammation. Again, the purpose of the heat is NOT heat therapy. You are just simply returning blood flow, and getting your leg ready to be iced again.
hope this helps.... get better soon, man. If you take it easy, you should be getting back into those long runs in no time at all. After I took this time off to rest, and strengthen I haven't had any more problems....
best of luck to you.