A.W.
It sounds like you've changed two major things for her in a small amount of time. You need to either wean her off the formula or off the bottle first. Then you can wean her off the other. It'll be easier on her.
To wean off formula, you start off with 3/4 formula and 1/4 milk. Following week, it's 1/2 formula and 1/2 milk. The last week, it's 1/4 formula and 3/4 milk. The week after that, you'll just give her milk. I used the same technique with my two oldest and it worked great.
As far as the cup is concerned, simply put, you're gonna have to bite the bullet. Have her drink from a cup. Start off with a meal where you can sit by her and hold the cup for her when she needs a drink. Pain in the rear, I know, but it's the quickest way to get her on the cup. She's too young to hold it themselves. But, she sees everyone else in the household drinking for a cup, and children are ususally eager to do things like grownups.
After she gets used to the cup (however long that may be) you can give it to her whenever she's thirsty or during a meal. Once she can hold it herself, you can put it out of her reach until she's ready to take a drink. That way, you're not having to clean up lots of spilled drinks. ;)
I hope this helps. Good luck!