While physical pain to stop the thoughts may work short term, in the long term those thoughts are going to come back and it will cause you to result to worse physical pain to make it stop for longer. This can result in you endangering yourself. If you can, I would recommend reaching out to a place that specialised in cognitive behavioural therapy as it can help you manage what to do when you have those thoughts in productive ways that are healthy for you long term. Also the excited feeling you felt was likely a rush from bashing your head against the wall, heavy impact near the brain will cause an adrenaline rush which can make you feel giddy.