What do i do please help me with my bunnies?

If the runt is not getting any attention from the mom and seems to be thin (undernourished), I would do as the vet said and try feeding it yourself. In most cases if it is not taken care of by the mother it often dies. You will have to feed it with an eyedropper. You can get milk supplement from a pet store. Just follow the directions on the box/bottle. Also there is info online to take care of a bottle baby. And recipes for homemade supplements.