Suggest Treatment For Severe Headache

hi for the past year i have been having severe attacks of pain it starts gradually at anytime of the day and each hour that passes i become more imobilised ie my head lowers to my chin my sholders raise i cant move my arms and i have head spasams that i cannot control. this attack can last upto 2-3 weeks,i have been prescribed 5mg of diazepam 4 x daily and pain killers nothing seems to help. I am a 40 year old female