question: Hi, I have a hard lump on right side next to tailbone and started feeling pain Mon. afternoon. My tailbone was painful but been taking tylenol and the pain is more dull. I still can t sit back or lay on my back. I only remember sitting in a car for 2 hours on a day vacation this Sat., slept on a hard mattress Fri. evening, and bumped my bottom when making the bed Friday evening.