Good questions! If the point of questioning is to arrive at answers, then to question at all implies that there are answers. Even if "everything is subject to doubt" there are still the structures in place which allow for doubting at all. That means doubting can't be entirely negative, but requires other things to be in place in order to be what it is. It can be overwhelming, but hopefully you can also take a step back from the doubting process and see that it is an ordinary movement of the mind which does not throw away that which is doubted, but rather retains it in a different way which no longer takes it for granted, and gives it a kind of life or space to follow its own movements. Doubt is an implicit function of the mind, so there is surely nothing about it to be troubled by in itself.