You could try a nipple shield and put a little formula in it so when she ***** it will be instant gratification. Then she will continue to suck and get breast milk. Pumping helps to increase milk supply and you could pump and feed while you transition.
Just nurse as much as possible. Even a couple drops in the first few days are enough because colostrum is very calorie dense. Work with a lactation consultant since you got bad advice at the hospital.