Ability to eat for children with cerebral palsy?

The child i take care of and love like my own is now tube fed. He loved to eat before. I started feeding him baby foods at a year and a half then we slowly moved up to more solid foods like breads and pastas. He is four now and last year after his swallow study, the doctors deemed it to dangerous for him to eat or drink anything by mouth. He now has a G-tube. The tube works great but he is always wanting food like ice cream and whatever he sees other people eating. How can I help build up his control enough for him to be able to eat normally again, or just give him a drink of water? The problem lies with controlling the muscles in his throat. Everytime he fails a swallow study, it's crushing for both of us. I want it so bad for him, not to mention he sometimes gets infections around his tube. What can i do to help him?