low blood-sugar can make you feel really sick and make it hard to eat. i think you need to go to your gp because this sort of weight-loss in such a short time needs to be checked out to make sure there isn't something else underlying it.
rather than trying to eat a meal, try little and often. some fruit-juice (dilute it with a little water if you like) and something like a rice-cake or ritz biscuit to nibble slowly will help. try to do this every hour if possible and see if it helps, hugs, Judith xxx