I purposely banged my forehead on a wall last night multiple times cause i was angry. now i have a huge lump and a small scratched area. its sensitive to touch. dont have a bad headache but its there. should i be concerned?

If you did not lose consciousness, you may put ice on the lump, After a day or so warm fomentation will help in the resolution of the blood in the tissue/hematoma. Please seek assistance from a mental health provider to deal with your self-destructive behaviour. Wish you good health!

I too would focus on dealing with self destructive behavior, and suggest seeking appropriate counseling. I doubt you have caused any intracranial problems other than superficial scalp trauma. If blurred or double vision, dizziness or imbalance, nausea or vomiting, progressive headache, etc., seek medical attention.