Can functional neurological disorder cause quad weakness, numbness, parasthesia? both sides. face too. no seizures but huge neurological symptoms without agreement of organic cause?

Would advise ASAP, obtaining a full independent neurological assessment at a major medical school, as you are in great need of pinpointing whether your issues are organic or emotional in origin.

It is not feasible to provide a meaningful opinion without taking additional history, physical examination and may be some tests. It would be prudent to see your doctor and discuss if you may be depressed. Counter-intuitive as it may seem, exercise may help. Start with low intensity exercise such as walking and gradually increase the intensity as tolerated. Drink more water. Wish you good health!