Hidesrtidy/Lil, welcome to the forum! Please be sure to read the information in the folder at the top of the page entitled Hepatitis Resources.
Having diabetes is an additional challenge for a hep C patient. As far as the Lactulose and Xifaxan, if you are with him when he needs to take his meds, go to him with the pill, liquid, and say, "Time for your meds." Don't leave it up to him to take them or nag him to do so. You know how nurses do this in the hospital? Same idea. And don't leave his side until he takes them. Make it a business-like thing instead of an emotional one. Other members may have other ideas.
Be sure to check out the Caregiver's thread, too.
Hugs,
Connie