Help! My Hair Pulling is Getting Worse

i thought i was getting better but i'm just reverting back to how it started. i have a massive bald spot on the top of my head and it actually hurts because after i pulled all the hair from there, i just started scratching at it. (this is going to get somewhat violent). sometimes i just want to take a knife and cut off my scalp. the aching and itching is almost unbearable. i've put ice on the top of my head to distract from it, i've ran cold water over it for close to 5 minutes, and it only gives me temporary relief. i don't know why it itches. i've checked for lice numerous times, and i'm not sure what else would cause it to be itchy. sometimes i think it's like phantom itching because i first started pulling when i *did* have lice. does anybody have any advice?