brittle, flakey weak nails

I have had awful nails since I can remember. Lately they have become even worse they are very brittle, flakey and weak. I haven't worn any nail polish for years even on special occasions as the remover makes my nails even dryer. Does anyone know some special remedy or hints that could help strengthen my fingernails. I would be grateful for any advice, I have tried many potions and lotions from shops to no avail.