I would try to find a vet that is interested in learning about B's or know's about B's. It took me a while to find a vet that would listen to ME and not the average shoot em up/shove it down mentality.
Try a warm bath for the BM. As for the frontline and intercept they should be able to be held off. I don't use flea med-my B's don't tend to get fleas. If it's for the heart worm only wait a few days til she feels better and then give it to her if you need to use it where you are. I know here we only use it til November.
If you want a basic food, as Sharon said-chicken and rice is the easiest on the tummy. You may want to make your own for the moment-boiled chicken and rice.