In addition to the above, difficulty eating, chewing, swallowing, unplanned weight loss is also muti-factorial, so each needs to be addressed, treated, such as mucositus, dysphagia, trismus, xerostomia, food aversions, sensitivities, anorexia, metabolic changes, and any fungal, bacterial or viral infections that can prevent obtaining adequate nutrition, hydration.
Good luck with everything.