New large bearded dragon help, hates water? How can I train him to trust me?

Now is the time for tough love and patience. Don't give him any more protein. Just leave him a bowl of greens and when he gets hungry enough he will eat them. You could throw in some freeze-dried mealworms to peak his interest. I don't know what you mean about him not liking water but if it's about drinking it don't woory. They usually don't use it when you're watching but leave it there anyways. If it's because he hates baths just leave him alone for a few weeks. It's going to take him awhile to get used to you before you can start trying to handle him.