Hi PROfb03, welcome to de-lurk mode. Sounds like you've got more than just not eating enough going on according to your various lab tests. I think it's a lot more complicated than just hey dude, eat 4,000 calories following these specific macros and lift some heavy weights.
. It's great that you continue seeing a doctor to get to the root of your problem. Just looking at what you wrote, I would say that you can definitely lighten your workload until you find out what's ailing you. Your body doesn't need the added stress from the Dos workouts, HIIT AND biking. Try to de-stress a bit. Eat healthy and enjoyable food in amounts that make you feel full, do your MHPT workouts and maybe do some additional walking or "light" cardio for a while. Once you get a diagnosis you can increase your workload.
I hope you get an answer soon!