Is the bolt misthreaded?
Sorry for the late reply. Been really buzy
Try placing a flat bladed screwdriver under the washer as you undo the nut. Keeps the bolt in place and twisting it will add a bit of extra pressure when trying to remove the nut.It does turn when i loosen it and when i tighten it however, i cant fully remove the actual bolt
Just get a new bike!Reading through three pages I have come to the conclusion that in view of the difficulties being experienced by the OP the best solution would be to purchase a complete V brake assembly and install it. It’s not expensive and I’m sure that many commenting, like myself, are losing the will to live.
Just get a new bike!