Please don’t stop praying or trusting in God. But the other side of the coin as I’m sure you know is we are to do what we can as well. It’s very sad, but you can only “lead a horse to water, you can’t make it drink” as the old saying goes. My heart goes out to you as I’ve been in a similar position with someone close to me, though it wasn’t for anxiety but another condition. All you can do is keep trying to convince him to take his medicines, see a psychiatrist or a psychologist as well. I’m not sure, but isn’t there a section under the law where someone can be forcefully admitted to the psychiatric ward of the hospital and kept there until the doctors discharge them? This happened to my relative.
Mary, mother of Jesus, please be a mother to this person and David and obtain the help he so desperately needs, now. Amen.