Sorry about your fever. Get better soon.
I believe your temps are just too high. Like I said, my indigos are at room temp for much of the year (except for winter). Your hot spot is way too warm. The snake is dehydrated. Consider turning the heat off entirely, especially in summertime. I have six indigos and have never had this problem, but I never get above 80 degrees. Sphagnum should be ok, but keep it wet.
My main point - your temps are too hot. It is a simple fix.