I won't go into detail, but I will tell you what I've learned from watching my family and others. Families tend to orbit around one another. Sometimes they take turns orbiting around each member. Sometimes they just orbit around one family member.
Families that orbit around one family member tend to orbit around their "favored" member or their "problem" member. In each instance, they can be so focused on the one who's pulled them in, they are unaware of what's happening with the others outside of their immediate concern.
If you feel as if you are standing outside of your family's circle, my heart goes out to you. Please realize you are just as worthy of their attention and love as the family member they are focused on, but they may not be able to show it to you. Let go of that expectation. The gravitational pull of the situation may be too strong to expect a break in family patterns. Family attention and approval does not make you more worthy. You are worthy from being the person God created you to be.
Be that person. Forgive your family for their humanness and set boundaries if you need to do so. Then go live. Love on others the best way you can and forgive yourself if you get pulled into an orbit of your own. Life is too fragile and short to hold grudges against others and ourselves. Go do. Go be. Go live.