Is this a form of anorexia nervosa?

Yes it is still considered to be called anorexia nervosa because you are not eating. It seems like to me that you are suffering from depression because thats why you want to feel the pain. I like feeling pain too when I am depressed. I used to be bulimic so i would make myself throw up 3x a day to feel the pain. I dont know how i started doing that but I continued and it got so bad that I would cry and I just wanted to throw up even more and this lasted for 2 years. Eventually i stoped because I promised i wouldnt do it anymore but i still think about doing it sometimes. You just need to overcome it and find something that would help you like running. Running helped me a lot because I would keep running till it hurts then i would get runners high and this is a healthy alternative than what I did before.