Yes Steve. Accept the help. No one can help you if you won't help yourself by being willing to be helped. All through the entirety of our lives we whistle past the graveyard in denial of death, all the while knowing that life is temporary. Everyone has an end out there lurking, waiting for us to reach our clock's final tick. Regardless of what happens with Joan yours has not come yet. Pain is part of life and we either accept it, heal and let life go on or we can let it destroy us. No matter which way we choose the emphasis is on the "let." You choose which way you go. You do not have to blame yourself. You do not have to race out and find someone else. You can be the master of the things you can control. You can't control Joan having a stroke. Sorry, but that is above your pay grade. You can, however control how you handle it. It's okay to feel pain and even guilt in the proper time. Now is the time for you to be there for Joan. Pull yourself together and be there for her. If those last 20 years you mention mean anything to you then you will honor them by being there for her. I'm sorry if that sounds harsh but as your friend I have to tell you the truth and that is the truth. I love you brother, let us help you, let doctors and nurses and social workers and cops help you... PLEASE.
