You aren't alone. My girl is also a growly sometimes nipper who prefers playing to being touched. Ball is her favorite thing, so we touch her, mark with yes, throw the ball. We also taught her to choose when she is touched by teaching her to touch her nose or the top of her head to an outstretched hand. She has gotten better and now solicits petting sometimes. She still gets growly and nippy if she is overwhelmed or irritated by touching. It has been an ongoing process. She is also particularly cranky about being touched on the couch. Our behaviorist taught us a protocol with a clicker and treats for hand shy dogs.
Skadi, AKA Lady Wolfington, GSD 4.6.12
Grim, AKA Bones , GSD 7.7.13