Not everyone is blessed with the loving, stable, wonderful family they long for. Your birth family is full of conflict, blaming, and taking sides. I don’t know why this all started or why it keeps going but you don’t have to stay in the thick of it. Since it seems like they aren’t interested in making things better, it may be time for you to “make” a family that’s more to your liking. Stop wasting your time trying to get a family out of the group you were born to. By all means, do what is required to maintain contact and be civil but put your energy, time, and love where it will pay off.
Some people are lucky enough to fall in love with someone who has a great family that welcomes new members. If that’s your situation, accept it as a wonderful gift and become a full participant. If you haven’t found a family through love, nurture the friendships you have and add more with an eye to finding people who are admirable in the way they conduct their lives and who are supportive of their friends. Be sure to include some older people whose own families may be at a distance from them. You will benefit from their wisdom and they will appreciate your interest. Also look for younger people whose families are far away and who would appreciate your mentoring. Then work on getting all these good people connected by introducing them to each other and inviting them to share in some get-togethers. Do your part by doing random acts of kindness for individuals and hosting group fun.
Real friendships (and families that care) require attention and effort. In time, you will find yourself surrounded by people who care about each other. As far as I’m concerned, that’s what life is all about.
I wish you well.