How about joining a group like TOPS? There might be one near you. Or you could start your own group. I don't think you need very many people to start your own chapter.
If you started your own chapter, you could have the meeting right before or right after the guild meeting.
There is an annual fee/dues - and most groups have dues -
There is also Overeaters Anonymous - which did not have dues - but in my limited experience, I found the TOPS group to be a lot more positive.