What's the best flea meds for a dog she was on bravecto from the vet but it made her itch really bad and had a bit of a rash from it?

Ask another vet

Bayer Advantage works well but make sure you ask the vet first since the Bravecto is probably still in the dogs system and you will probably have to wait 30 days.

The one your vet recommends for your individual dog, as you've already discovered, not all are suitable, for All Dogs, you should have advised your vet of the adverse reaction your dog had giving the vet the opportunity to correct the problem instead of asking strangers/children on line, who know nothing about your individual dog.

Obviously if you're capable of addressing it with us, then address it with the vet, and while your at it question all possible side effects of other products, as well.

If your premises is infested it will do nothing for those, you'll need an exterminator and a lot more to be done before all will be eliminated.

Get her flea dipped (bathed) at the vets and try a flea collar. No more fleas. Chances are they're also indoors now. Wash her bedding and bomb the house while she's at the vet's being dipped.