At Wits End No Answers

1 year ago my husband weighed 176 lbs, today he weighs 138! He is 5' 10" 77 yrs old. August 2021 he had colonoscopy 9 polyps taken, then enterscopy with vessels cortrised. He had iron difficent anemia, put on iron pills, then had to have 5 iron infusions. He has had type 2 diabetes for years. For approx 4 years tremor in his right hand. He has had every test known to man and the doctors say all is fine now, A1C good, no anemia, all test good. In April he had Bells Palsy which is just now clearing up. He has lost muscle, and looks frail. Until a year ago he seemed fine. He has also lost some memory. I want him to be checked for Parkinson's, the doctors just say its his age! He has been active all his life, it is hard to watch this, and I do not believe the old age theory, I know something is wrong. I am scared and at wits end.