It would be very hard to be going through it, but if it were my father, I would take comfort in the fact he belongs to Jesus and if he should pass away, I know he would be going to be with Him. Re: Warfarin- this is an anti-coagulant (anti-clotting medication, commonly known as a blood thinner) and is prescribed because of the clot - I believe to try to get it to break up so it will not plug a blood vessel anywhere. Is he continuing to take the Warfarin? Did they change him over to Plavix? Perhaps you might consider something like Ensure (but something with NO vitamin K in it because vitamin K can cause clotting) for part of his fluid intake if he continues to lose weight.
Regarding the five weeks wait for the specialist- this would not be something I would accept without fighting every way I could to get him in sooner. I'd be on the phone with member services about the access to medical care problem and the gravity of the situation and how you feel your father can't wait that long. I'd put it in writing in the form of a grievance as well and make a copy of it before mailing it certified or faxing it and hanging on to my confirmation.
Ultimately, your father's time on earth is in God's hand, and if it were my father, I'd be praying a lot about the situation.