Welcome to the SR family!
Thank you for taking the time to introduce yourself and share your story with us. Some of our stories are in the sticky (permanent) posts at the top of this forum. Also, lots of wisdom in those posts.
Wow, that is quite the endeavor to pack up and move to assist your younger sister! How does she feel about this change? Does she want you close by to help her on a day-to-day basis?
The rest of the family.......well they are adults and they will live their life as they feel is best. I have had to learn to "let go and let HP" (HP is higher power). I have learned to do that by detaching. SR (this forum) and Alanon meetings have helped. Also some self improvement books like "Codependent No More" by Melody Beattie have helped.
Give the Alanon meetings a chance. I try to remember to "Take what I like and Leave the rest". I live in the Bible belt of the southern USA, and most people at my groups refer to their HP as Jesus. I am not Christian. I have learned to love them just as they love me.
Keep reading and posting.
We are here to support YOU