Hi there ~
The knot may be old unhealed scar tissue from having fallen and getting 6-7 stitches during your childhood. A nerve
impingement in this area can cause you to have pain in the area that the nerve supplies. I hope this is not the case. However, I empathize with your condition. You might need surgical intervention if the pain is intolerable. I hope this helps. I am sorry to hear about your condition and please seek the help of a good neurosurgeon.
I hope this helps. Take care and have a lovely day !