I am so sorry to hear of how you are feeling atm. I of course don't know all of the history and the dynamics of it all...
...but I know no one should feel abandoned and rejected by their family. :/
I think the best advice I can give you is to never lose your sense of self worth due to anyone else's behavior.
Never let someone else define your sense of self.
You are a good, kind, caring, smart and loving person. I see that clearly, just from knowing you here.
You can't choose your family, but you can choose your friends...so perhaps focusing on cultivating your relationships of choice should be your focus for now.
Don't close off communications with your family of course...be
open to healing and reconciliation...but neither should you keep banging your head against the same door so to speak...
Hugs my friend. Remember who YOU are...and know that you are loved by many.
"Courage is not the abscence of fear, it is feeling afraid and doing it anyway!"
"Worrying does not empty tomorrow of its troubles...it empties today of its strength."
Corrie Ten Boom
Panic Syndrome recovery due to CBT