Fillings vs crowns vs ??

Hello, to keep this short, I need a lot of cavities filled on almost all my top teeth and some on my bottom. I already have fillings on all my teeth, some more than once. My last dentist quoted me around $1,600 to get everything filled. Another dentist recommend crowns on 6 of my top teeth that you see when I smile and then fillings for the rest. That quote was a little over $8,000. You can visibly see the cavities when I smile on my top teeth and it’s my biggest self conscious.

My history/best guess for why my teeth are so bad is when I was in elementary I had braces and also didn’t brush my teeth like I should have. In middle school I used whitening stripes daily for way too long and lost a ton of enamel and have had awful sensitivity ever since. I started vaping in high school and am only now quitting (6ish years) which I know that dries out your mouth. Also was diagnosed with Graves’ disease shortly after highschool and am now on levothyroxine for the rest of my life (that pill is known to dry out your mouth).

I only drink water and green tea, eat healthy with absolutely no sweets. I brush with prescription strength floruide tooth paste 2 times a day, floss day and night, and use mouth wash. I’m down to 2nic and once I hit 0, I’m done (so I’m down within a month). There’s no other pill I can take other than levo for my graves and if my dry mouth persists, I will always be prone to cavities. I wake up with an extremely dry mouth every day.

My dentists told me if I chose to get fillings, that’s only a short temporary fix that will probably have to be redone every 2 years. Though crowns only last 5-15 years and since I’m still so young (23) and will always suffer from dry mouth, I don’t see them lasting that long. Meaning I’ll have to spend $8,000+ atleast 3 times in my life (maybe more). Theres one more option I’ve been considering.. but I really need some opinions on all of this..

I personally feel that my teeth are done for, this is not reversible and will only get worse. If I’m getting recommend crowns at this young of age, I feel like I should just go all in and get permanent dentures. If my teeth are truly this far gone, why don’t I save even more money in the long run?