Insurance and Botox

I'm new to this site and feel like I'm finally with people who understand my world.  I work part-time instead of full time because I've had migraines for over 30 years and cannot work regular hours.  Luckily I've found a job where my boss understands my condition and will allow me to stay home if I have a terrible migraine.  My gripe concerns the insurance companies refusal to cover Botox injections for migraines.  I had them several times about a year ago and they were the first hope I've had of getting rid of these headaches.  After two or three sessions my insurance company stopped payment and will not pay anything towards the treatment.  I've tried every medicine under the sun...and most migraine meds (Imitrex, Maxalt, etc.) do not seem to help me either.  I feel like I'm only taking pain meds when I get a headache instead of doing something to prevent them.  Has anyone else's experience been similar????