Hi. Thanks for your query. Read and understood your history. It is the hematoma on head injury that causes the lump. Once the hematoma dissects the skin and other tissues the nerves get stretched and cause sort of Neuralgia , hence the typical tenderness , sore to touch. I would advise you the following: Get the hematoma aspirated to reduce the pressure. Cold compresses help Pressure bandage after aspiration. Anti-inflammatory medicines. CT scan to see the local and internal problems to be on a safer side. I hope this answer helps you.