What can I do about my deer mount losing its hair?

I have bought and watched bookoos of videos and no one has mentioned a solution to my problem. I am mounting my very first buck. (first mount as well) I don't understand what I've done wrong. I just got my mount on the form and the hair is falling out in clumps. I have already eaten the meat from him and I didn't get sick... so I don't think he had health problems. He was processed, skinned and put in the freezer in less that 24 hours and I just defrosted him yesterday to mount him today. I'm stumped. Any ideas on how to fix it or at least minimize the hair loss? Thanks for your help!