Same here. Been eyeballing a $600 RO system from Menards for fluoride removal. Our fridge has filter that we change often and it shows in clarity, taste, and according to my tester, but no help with fluoride obviously.

In meantime we drink bottled spring water. Cook and do coffee/tea with distilled water.

U prolly know, but someone reading may not, if u go RO, you will need to add back in minerals with an extra RO system part ( more expensive ones may do this for you ) OR take supplements or drink electrolytes. RO removes everything, including the good stuff, but still outweighs taking poisons just to get some minerals.

I feel ya on the cold showers. Rough. I know it'll get easier and I do feel better and more productive when I take them, but damn. Takes practice. Still battling that one.