Hi and welcome!
I've also had nails affected by psoriasis at various times, ranging from slight pitting to painfully deformed nails, although never to the point of falling off. It tended to be the front part of the nail that would come away from the nail bed, although once the skin around the edge of the base of the nail started to become affected, then the whole nail would begin to feel looser than normal.
I don't think there's anything you can do. If you can find a systemic treatment that can clear your psoriasis (whether oral systemics or biologics), then it will also tend to help with the nails too. Are you seeing a dermatologist at the moment?
My advice would be to keep the nails short as it can become easy to catch your nails on things otherwise, which can be quite painful when your nails are bad. Also, try to keep the skin around the base of the nails moisturised, as it can become quite painful when it starts to crack and become dry.
Hope that helps.
