Hello, I am new here, female and a RN. I am sorry for what has happened to you. As an aside, 3 years ago today I had back surgery that left me with chronic nerve and other pain and a host of disabilities, so I can empathize with how it feels to live in a "different" body.
Depending upon the state in which you live, there is a statute of limitations within which you can attempt to bring a medical malpractice lawsuit. Sometimes it's from the date of the surgery, sometimes from the date you discovered the injury.
My real reason for posting is that I hear desperation in your post. You do not say if you have seen a neurologist or a pain specialist. While I am not familiar with nerve damage to the scalp, I had nerve damage to my spine (no,I could not sue; nerve damage and death are potential "problems" with back surgery, LOL). There are medications that can be used successfully for nerve pain of different origins; I urge you to get yourself evaluated to see if there is a way to alleviate your suffering. Best of luck to you.