How can I get POA for my unconscious parent?

You cannot get POA from an unconscious person. In that case you either go by your state's "next of kin" laws or you seek emergency guardianship.

I second what mom2mom said. Quote from a legal site: "One crucial thing to know is that the person who is the grantor of the power of attorney---in this case, that means the person who is suffering from dementia or Alzheimer’s---must be able to understand what they’re signing. This is to protect from instances of elder abuse, graft, and other crimes." Hope that is helpful.

You would either have to wait until they become conscious and able to make decision or you will have to petition the courts for guardianship. You can't "get" POA it can only be given by the person.