Hopefully this isn’t unwanted advice, but I have also cut out a lot of meat from my diet and I started getting weird side effects. (Lost feeling in my hands and feet, got dizzy a lot, felt extra stupid.)
After seeing a doctor, I take vitamin B and D supplements and it helped a lot. If you can’t see a doctor, you might consider trying some vitamin B and seeing if that helps. Apparently lots of vegetarians and vegans take it too.
When you take them off at night, don’t put them lens down directly on furniture or anything like that. You will scratch them. You can either set them on a microfiber cloth face down, lay them the other way (lens up), or get a glasses stand if you’re feeling fancy.
You could use your glasses holder, which is what I do when I travel, but I find that being able to access my glasses quickly is more valuable to me.
Also I get discount glasses from Zenni, Costco, or Eyeglass World. I never get just one pair because I am forgetful. If you can swing it, I would get at least one backup pair.
When you get a new prescription, you can keep one pair of the old glasses in case something happens to your current pair(s). (The plan being that you will not be completely screwed, you’ll have a “close enough” pair until you can rectify the issue.) If you do that, store them in a case and label the case with the date you got that prescription. I would only keep at most one backup from your old pairs.