What should I do, I'm scared of messing this all up...?

I'll finally be moving out of my parents' house in the next couple of years and on one hand I can't wait. My mom doesn't know me anymore at all, she only thinks she does. Almost 8 years ago a dear friend of mine died and she refused to let me attend his funeral because she thought she was protecting me. Her parenting style took over and she was blind to what I actually needed (to be there) it was her way or no way and it drove a wedge between us. We aren't on the same page about anything and it really upsets me because I want a better, deeper, relationship with her. I really do. but every time I dare open my mouth about that funeral and how it hurt and I think we should have an honest talk about it she either starts yelling at me or belittles me relationship with that friend and acts like it was a passing childhood phase and I have no right grieve for him and never have. it's for this reason that I have yet to tell her that I've converted from Methodist to Orthodox Christianity and now she doesn't have 1 single clue about the deepest part of my life. If she can't recognize my thoughts and feelings about something she was there for and should understand as valid, how am I supposed to tell her about the slight change in my faith? I have to. I know I have to because if I don't I'm scared it won't be long after I move and we'll be strangers to each other. Please, Help me, what would you do?