Picking up wet dough
If it is turning to "slime", losing shape, and becoming sticky again, you are probably not building enough strength in the dough.  First, I would try the same recipe, holding back 50 - 100 g of the water.  Work with a slightly lower hydration until you get the feel for things.  Then, make sure your initial kneading/stretch and fold takes at least 8-10 minutes.  Subsequent slap and folds should be 1 set (to me that is like four folds, which reshapes the dough into a sort of ball), spaced by about 30 minutes. I use no flour on counter, even with very high hydration. Initially, with a wet dough, you will get a lot sticking to fingers. This will reduce with time and the building of the gluten structure.  For final shaping, either a very light dusting of flour (often none), but a wet bench scraper and wet hands usually does the trick.

High hydration dough is tricky. I really had to work up to it to understand the behavior of the dough.