Efflixi:
What you do in your situation is get as much out of life as you can in the time you have. Doing what you enjoy whether that is travelling, doing sudoku, or whatever. As others have said, having a blood relation doesn't have to be an unbreakable bond which can't be ignored. You are not your DNA. You are the person who lived your life, with the choices you made. The results could have been very different if you had made other choices, but you would have the same DNA.
Personally, in your situation I would just walk away from the family. You have already distanced yourself, time to just "cut the cord". Good luck and best wishes.
“Extinction is the rule. Survival is the exception.” -- Carl Sagan