Pete, don't be hard on yourself, we can only do what our bodies let us do. Your stepmother will be with you always, and she will understand that your health just would not cooperate. She would not want you to suffer more if you did go. I'm so sorry about your loss, but you tried,lining up the flowers getting yourself prepared to go and then bam, Tha RSD kicks in and there is no way you can go, That happens to me with crazy things even fun things that I am looking forward to that when the time comes I can't go, it sucks. Don't ever think badly of yourself because you can't do things, it happens to all of us. I can't even count the things I've missed good or bad. Give yourself a break, Remember your stepmother knows how you feel.
Your friend Wendy