@onana I'm off 13 months of daily Big 3 since mid Feb. (had to substitute Ciprofloxacin for Azithromycin for the last half of treatment because of ototoxicity). I had dry mouth before starting, but worse while on the meds, and I also had the change of tastes and the burning tongue. I tried meds for yeast for the tongue, but they didn't really help. The only thing that worked was eating yogurt which I don't really like. But it was worth it! The burning never completely went away, but if it got better and I began to slack off on the yogurt, the burning would come roaring right back. I also ate kefir with fruit and honey and that worked too. For the dry mouth, I use Xylimelt tablets at bedtime, one in each cheek. I like the mint free ones. And during the day, I use Biotene mouth rinse for some short term relief. I think it helps relieve the burning a bit as well.
My infectious Disease doc advised me to continue probiotics for 6 months after stopping the antibiotics, and I have continued to need the yogurt as well, although I think the burning tongue is beginning to need less attention. This whole business (disease and treatment) is certainly an adventure!
Hope this helps!