Hi you cannot say, welcome to our community. You have had to face a lot and for that I feel very sorry.
I have a question, how did your mother adopt you and have your father thinking you were his child?
You are correct about the genetics so it is lucky that you are not like the others, your mother loved you very much and like a real mother would. I am sure she must had died with quite a burden but found comfort in knowing you were there.
It is indeed terrible what your head of the church did to you. Personally I am not into organized religion but I do realize many find comfort there.
I think you are very wise in how you handling these other people in the family, they sure know how to run when they don't see money in their path to grab. It is a good move that you extended out the payments to be able to see clearly what your next move should be. Here we have an expression, if you don't like the family you have, best to find a new one more suitable for you.