Insurance plans

I was wondering a few things in hopes someone can advise or has posted about this.

I am a migraine sufferer since the age of 12 so now 30 years. My job keeps giving horrible insurance plans and my treatment and care keeps getting hindered. I'd love to know what insurance plans other patients find as the best for their care when it comes down to Botox treatment (approvals for high doses-I get 300 units), other migraine medications, hospitalizations related to them, etc. Don't even know if there's such a thing as someone who advocates for patients who suffer with migraines and get no where with their insurance companies, advisement, and so on.
My newest insurance is Cigna and they will not approve my full Botox dose I've been getting for years. I've had Meritan Health by Aetna and they approved me in the past but only 3 months and prior to that plan I BCBS and UMR and I was able to get my proper dose and every 10 weeks but many medications still were heavily needing appeals all the time.