just stop going and say no more about it.
if anyone tries to meet with you in some formal way - make your excuses - say you are not up to it right now and will get back to them <like never>
if they insist on meeting just play it cool and say you aren't mentally or medically up to attending right now but as soon as you are you can't wait to get back to be with the brothers etc etc
they know its BS you know its BS but thats the way you deal with a BS cult