Suggest Treatment For Sore Lump On Thigh

Hi. I am a 23 year old woman. I recently went to the doctors for a few random lumps on and under my skin. Two were surgically removed and were not cancerous. Then there is a completely different type of lump on my thigh. The surgeon called it dermatofibroma. I went with that diagnosis and was fine. However, the past few days the lump has increased in size and is sore to the touch. I looked up dermatofibroma and the description I read does not fit what I have. For example, it does not dimple when pinched. I know to not always put much faith into what I read online though. I am just worried because of the recent rapid growth. My health insurance was recently cut to only pay E.R. visits and a PCP, but the PCP will only send me to a specialist, which would bot be covered by my current insurance. So I am just wondering if I should worry, and go to the ER to be seen, or stop driving myself crazy about it.