My sincere condolences for your loss, Janet
Your story resonates on many levels.
For being the one who offers an olive branch to an estranged sibling.
For knowing a mother expects us to obey, do the right thing.
For a brother who doesn’t know how to love and cuts the bond with us.

When you said sorry umpteen times, in your heart of hearts, who was speaking?
For who did you apologize?
For you or your Dad?
The reason I say this is because I once sat with my cousin when her mom died and it was her Mon speaking through me, “I’s so sorry” ~ EXACTLY the way you described this phone call.
You are a messenger of light.
These divisions are the most difficult to bear in life. Rule above any rule, your spirit and soul you honour first. Jay is responsible for himself. You do what can and then, it is up to him. His soul lesson, not yours.
Forgiveness is given to self when you know, have processed what/who hurt you and can move forward. Be kind. It takes time to heal.