Keeping a fan on definately helps. What kind of mattress do you have? I bought a memory foam mattress and woke up soaked. I found that leaving the fan on and putting 2 or 3 blankets on the mattress under the fitted sheet did the trick. The blankets allow air to pass between your body and the mattress thus eliminating the sweating.
I would wear less layers and get a fan, I also think it would be a good idea to go ahead and see your doctor. There is probably a reason you are sweating so much and your doctor will be the best person to help you figure this out. Best of luck.