Tinas -
This could be very serious, and you should get the vet out immediately.
It sounds as if you may have fed too much carbohydrate, and given her acidosis. If so, she'll need a stomach pump very soon or she'll die.
They must not be fed too much carbohydrate -- we never give more than about 2 kg (say 5 lb ) dry concentrate a day, with as much hay or straw as they can eat.
I hope I'm wrong...
Good luck,
Richard
PS - Where are you?