What should I do?

Two nights ago I discovered a painful lump in the back of my head on the right side. It's about the size of a dime and hurts to touch and all around it. Its hard, and when I went to my first chiropractor visit yesterday I told them about it and they did X-rays, today they told me they didn't see any fluid so it's not a cyst. I just got new insurance and the doctor they assigned me to is appointments only. The quickest she would be able to take me is in three weeks. Yesterday I went to urgent care just to make sure it's not cancer because it runs in the family, and they told me it's a "fatty tumor" and to get it removed surgically. It hurts, and also causes headaches, so I need to get it removed asap. I can't wait another three weeks to see my doctor, should I just go to the hospital? Would they remove it? If anyone had this before,  what is your experience? If I was to go to the ER in the morning, would they remove it? Help!