@sswonger Here is a link that may be helpful in answering questions about EBV.
https://ebvhelp.com/
It doesn’t surprise me he tested positive for the virus. Almost all adults have been exposed to EBV and will have positive EBV IgG antibodies. EBV IgM antibodies indicate it is active.
If he is feeling worse after the hydrocortisone wears off, it makes me wonder if it’s the adrenal insufficiency acting up due to all the stress he went through over a year ago. I’m no doctor and can’t advise on that. What I can say is don’t give up!!! Keep searching the best you can.
~Marianne~