About a month or two ago when I was going to sleep I felt a stinging on the back of my heel. I didn't think anything of it and went to sleep. The next morning I woke up got in the shower, and that same spot started burning and stinging. It hurt to walk on and looked just like a blister. I put some antibiotic cream on it and later on it went away. Since then at least one or two days of each week it will come back up and start stinging and burning and hurts so bad. Then it will go away again. Then just come back up another random day. Sometimes it will wake me up in the middle of the night. It feels like there is oozing or something trying to come out of the sore or whatever it is. This morning it happened again, except the pain was so much worse. I haven't been to the doctor.. What do you think this is? please help!