Calendergirl: like you, I spent years either allowing myself to be badgered into taking on things I did not really want to, or feeling guilty about refusing.
Finally, and I cannot now say, when exactly this happened, probably when I retired, I decided there was no point in shilly-shallying about this kind of thing.
Now, I simply ask myself, do I want to do this, or not. Then act accordingly.
You have said no to taking on the job and admit that you are just not committed enough to the group to want to take over,
Fine - so don't beat yourself up about it.
If you have not already done so, stop a minute and consider how badly you will miss this group if it folds. If the thought does not particularly bother you, then you have made the right decision.
We have spent years of our lives - most of the years we can reasonably expect to have, trying to do everything, wife, mother, dutiful daughter and niece, sister and aunt, housewife, taker-of-pets-to vet even although they were OUR pets, not MY pets, including that last dreaded trip and coming home to dig a much loved cat's grave, while our better half hid, not "being able to face it".
We have written reams of Christmas cards, letters of congratulation or condolence and had our strenuous working life to do perfectly too.
Surely we have reached the time of life, dare I say, the age? where we can decide on the basis of if we WANT to do this or that, whether we say "yes" gracefully, or "no" with a spurious air of regret?