my husband is going through radiation treatments. he had a malignant tumor in his neck and it spread to 3 lymph nodes. the prognosis looks promising, but everything tastes bad, he has trouble swallowing, and he's nauseous. needless to say, he's lost a lot of weight. i'm so worried about the amount of weight he's lost and the fact that he's not eating very much. he gets annoyed with me when i try to get him to eat. what can i do?