GO!!!! Even being on dialysis you have a life. Go yourself if you have to and enjoy yourself.
I think the problem in your family, when it is considered in its deepest psychological motivation, is not stupidity about the significance of dialysis for sociali funcitons but instead, just pure malevolence. By this exclusion, colluded behind your back, they are trying to label you as a freak, as the scourge of the herd, to be ostracized from the normal family.