Oh, my, LJ. You have quite a predicament unless his love and concern for your well-being could be used as leverage to get him to see someone.
I'd find the best doctor available (at Johns Hopkins, perhaps?) and make the appointment and let him know how much YOU need him to go - if only so you'll now how to care for him.
That's the best idea I have...........and he may be too stubborn and self-centered to care, but I'd think it would be worth a shot.
I surely wish you luck.
Nicki