Hey,
Firstly sorry for the long reply, I just hope I can help in some way.
I completely empathise as I've suffered from migraines since I was 11, and I'm now almost 38. At points my migraines were chronic so I was getting them daily and I too was heavily relying on sumatriptan during those times. I was on repeat prescriptions for 12 pills at a time, and I was pretty much taking sumatriptan almost every day, quite often 2 or 3 would be needed to finally nip the migraine in the bud but it was leaving me with horrible side effects such as feeling groggy and severe pains in my muscles, but I would have preferred that over my severe migraines any day back then! I was ordering new prescriptions every week and they were signed off by doctors continuously for a long period.
Eventually after probably 2 or so years of this cycle I had a doctor call me and say she reviewed my history and wasn't giving me anymore sumatriptan, I was so upset as I relied on this to work and explained this to her. She informed me I was on over 1000 times over the allowance of what anyone should be taking in a year period. I was absolutely shocked by this, and by how this had been allowed for so long. And it is true that it does cause you to get recurring migraines, it's a terrible cycle it brings you on and I think that's what made my migraines so chronic.
I reluctantly agreed to try amitriptyline and like yourself, I could not function on this. I was sleeping for 12+ hours a night, had no free time after coming home from work as I'd fall straight to sleep and would then be back to work when I woke again. I continued for a few months as I was told the symptoms would settle but they never did so I stopped taking that also, however it did limit the number of migraines I had a small amount.
I really was in a predicament because I couldn't rely on sumatriptan anymore due to the repeat prescriptions being stopped and limited amounts prescribed moving forward.
I had to take a serious look at what my triggers were, and there were many! I also had to look at alternative ways to treat my migraines moving forward.
I learnt that some of the following things triggered them (can't remember all anymore), so I done what I could to eliminate where possible:
Bright lights / long periods in front of computer screens without regular breaks / skipping meals / napping / not enough sleep / too much sleep / anything hormonal - periods, pregnancy etc / alcohol-hangovers / drinks with aspartame / certain alcohol like red wine... the list could go on!
When I had to stop prescriptive medication I looked at what else could help, and I found that aspirin is amazing for stopping migraines if you take it early enough before it turns into a full blown migraine. In all honesty, I know looking back I was taking aspirin far too often also, but being an over the counter pill I could buy and take as much as I needed.
I also heard about daith piercings (in the ear, please look it up if you haven't heard of its connection to migraine prevention). It's a piercing in an acupuncture point for migraines. I got my right ear done first, noticed my migraines were a little less severe but not that much had changed so I was in doubt of it's ability to help. But about 5 months later I got the left daith piercing done and I didn't even acknowledge anything until about a month later when I realised I'd only had a couple migraines and they were pretty minor in comparison to how bad mine normally were. After getting migraines daily for a few years, it had cut right back to one or 2 a month. Gradually over time I was able to cut out more things that triggered them, eg taking hourly mini breaks from my work computer to get water etc, and the amount of aspirin I was taking also lessened.
On the note of computers, or any screen time - tv/phone etc (and bright office lights/car LED headlights for that matter), the most amazing thing I found helped eliminate migraines was blue light blocking glasses. I now wear them all day every day even though my vision is fine, because it helps prevent migraines that were triggered by bright screens/LED lights. They're about a fiver, and it's the best money I've ever spent on an accessory!
My migraines are now better than they've ever been. I sometimes get a migraine when I'm on my period (had many during pregnancy but it was hormonal so couldn't be eliminated), and the odd one with stress. I would say I now suffer from a migraine every couple of months or so, and they are very rarely severe anymore.
When I feel a migraine coming on sometimes just a strong sugary tea can help as they're usually pretty mild now, and if it doesn't help some aspirin usually does it and maybe a cold gel pad on my forehead if I need something extra.
It really would do you so much good in the long term to try move away from relying so heavily on sumatriptan. I can't say whether the best thing for you long term is another prescribed treatment plan or something a little alternative, but if you're willing to consider all options I'd say do what you can alongside the doctors recommendation, such as daith piercings, blue light blocking glasses, regular acupuncture. I've also read that taking magnesium daily can help, try looking up vitamins that help with migraines.
I really do hope you find a way to get out of the cycle you're having with migraines, I truly understand how debilitating and depressing it can be. I would say anything is worth a try, to get you away from sumatriptan in the long run.
Wishing you all the best 🤞🏻 xx