I would suggest that you and your siblings need to decide if you prefer to abide by your father's wishes or to properly care for him, it does not appear that you can do both.
Candidly, the health issues that you have described sound like some form of mental illness and I suspect his condition will continue to worsen. Your family should seriously consider having a guardian appointed. A guardian is similar to a POA in that it allows the family to provide for your father's care. However, it is much more thorough as it would effectively put someone in the position of fully providing for the care of your father, it would be much like a parent having control over a minor child.
If you and your family is interested in obtaining a guardianship, you could pursue that remedy by hiring a family law attorney in your father's location or by going to the local clerk of court to obtain the template documents. If you proceed on your own, you could fill out the documents, file them with the clerk of the court and then begin the process.
Please let me know if anything requires clarification.
Also, several customers have asked how they may direct a question to me in particular. If you specifically want me to assist you in your legal matter, just put "FOR JOSEPH" in the subject line and I will gladly pick up the question as soon as I am on-line.