The only reason the union leaders will ever look out for you is if it is in their best interest to do so. As long as they continue to be paid for their efforts or non-efforts, they can do as they please. And there is no one to tell them otherwise because they have taught their membership to follow them like sheep.
So besides continuing to blindly follow them, you have two options. You can either take matters into your own hands and do what is best for your family and what's left of your career, or you can call out the union and make them do what you want them to do. I'm assuming there is some control over who leads the union and in what they do. If not, that's a pretty crappy situation ripe for corruption and mismanagement.
Anyway, if you love being part of the union, make it work for you and not the other way around. If it is for you, then act like it instead of walking in circles for practically nothing.