>>519645534 (OP)
I drank tea for a while without knowing it's full of fluoride. Never really felt a difference but it has caffeine so that probably evened out the lethargic feeling. I do feel a difference if I switch water sources to one with fluoride, it's just a lethargic feeling and your brain is just static, unable to focus.
Topical fluoride on your teeth does nothing, you spit it out. Don't worry about it. I switched to hydroxyapatite paste only and after a couple months had cavities. Started using fluoride again and they went away. If you're worried about it, you don't need to use fluoride paste every time you brush. You can use it once a day, every other day, maybe once or twice a week. But I bet you won't feel any different, it will save fluoride going into the water supply when you spit it though. It's not necessary to use fluoride every day, but hydroxyapatite is a must. That's what actually remineralizes teeth, fluoride doesn't remineralize but it strengthens existing enamel.