I am sorry to hear that things are taking so long and you are hitting some road blocks. Hang in there, you will get there -just keep being persistent.
I don't know what to say about your family as family dynamics are so unique. Maybe they did not have you go on vacation with them because of the money issue? Or maybe they were not sure on how to navigate this new world and vacationing with you? Next time a vacation opportunity comes about, you could mention that you read some great guides like AAA Barrier Free Travel, Accessible State Guides and 101 Accessible Vacations. They might get the hint that way.