Jennel, Welcome to the site. Sorry you had to be here, but hopefully we can help your Dad get on the right track. What type of cancer did your dad have, was it tonsil or tongue or somewhere else? How is it rated, ie: stage IV, III, or something else? We can help a lot more with some specific information. It would be good if he joined this site and could give us some information. I can say that as Dani mentioned above, your dad is at about the time for things to get better. I had bad vomiting and bleeding after chemo and rad treatments as well, most of us did. That's just part of the treatment and quite common. You are right, also, that a positive attitude helps a lot in recovery and a negative attitude is detrimental to his getting better. Help him to be positive that this treatment, while it was difficult, is over and blue skies are just around the corner. If you accomplish this, things will get better for him in my experience.
With his reflux, is he taking medication for that? I had bad reflux all of my life and just started taking Nexium for it before this cancer thing started in 2003. My reflux is almost all gone and I take only Nexium now. I used to use 10 to 15 Rolaids per day, now am at 0 in months. The chemo is supposed to have helped that. At any rate, try to get him reflux relief. That in itself will brighten his day.
I also had a feeding tube and was very greatful that I did as I couldn't take anything by mouth for a couple of months after treatment ended. I only used Ensure type products so I can't comment on thicker things, but be careful because the tube can get stopped up and can be difficult to clear.
Let your dad know that he and you will be in my prayers. We can assist him more if we have more information.