Hello and welcome to our family, l am sorry to hear that your relationships with your father and your sister are complicated and makes you unhappy. I'm not sure that I understand what it was that your sister wanted from you by being kind.
I am glad that you have a doctor who believes you and who is willing to treat you. Many times, that is our biggest hurdle and it can have a great impact on our ability to manage our disease.
I wish you the very best and hope that things get better for you and your sister.
Peace and Blessings
Look For The Good and Praise It!