Do I have to make a brachah on tums if I really despise the taste and am only using it for stomach acid?
You don’t have to make a bracha on it. However if you can eat something else ( not water) and make a shehakol on it, that would be preferred. if you can’t then
The poskim discuss what is the halacha regarding taking pills that are bitter, but have a sweetener added to them. See Nishmas Avrohom 1- siman 204 (5), that R’ S. Z. Auerbach zt”l and R’ Neuwirth zt”l held that we don’t make a bracha on it. On the other hand R’ Moshe and R’ Ovadia Zt”l held that a bracha should be said. In our case it is even worse, since you don’t like the taste of the sweetener so there is room to say that it is as if it wasn’t added at all. Therefore there is a lot of room to say that you don’t make a bracha. Nevertheless, R’ Stitzberg shlit”a (author of Shaarei Habracha) told me that if you can exempt it with something else it is better.