I was driving home, oil pressure dropped completely down to nothing, started running very rough and died. I checked the oil and was low, but not dry. there was still oil on the dipstick. Now the truck wont start, it wont turn over. It just gives 1 single strong click like its seized up or something.
From you description, it sounds as though your engine lost the oil pump then seized. If this is the case, it will require either a complete long block or a rebuild to fix. You'll probably want to take this to a qualified mechanic to have it verified. Mind you, the oil pump on any engine usually doesn't just give up. They will last the life of the engine and beyond. There are some, however, which do die and when it does, gives the spectacular results you have described.