You have it! It will take time, firm boundaries, saying things like " hands are for holding, not hitting honey" and hugs hugs hugs...
It will be important that you show her your dislike or disapproval of the behaviors she has picked up, and at the same time, counter that with examples of the right way and lots of approval for that.
Time is the answer and lots of love and redirection. I feel badly for you and she that this has been a part of your lives, but you can redirect and teach her that love is not mean....
Don't despair, your sweetehart is still in there...
Please keep in touch here and let us know how all is going, ok?