You have to be in a position to be calm and comfortable and keep a clear head. No writing or efficiency advice works if you do not establish this first. It is trickier than one would think and I did not know this before I first lost this kind of situation — did not know what it was like not to have it.
There are various resources you need, material and psychic, to have it. This knowledge is why my writing advice is apparently unlike everyone else’s writing advice.