Should I open the beesnest

I have all my life lived in a rather weird family, and have found in later years that this has had a pronounced bad effect on my personal life how I work inside.

Two years ago it spread into a severe depression, and professional advice was to take the discussion with my family to air the past problems.

Im not sure I am able to.

A little background to help you understand why.
I have a father, a stepmother (who has been my mom since I was 3, so I call her mom, and cant even remember any other), 1 bigsister, 1 bigbrother (who never lived with us, so in effect wasnt anymore than a cousin) and 1 smaller brother.
My sister is my full sister, my small brother my half brother, and my bigger brother not related by blood.

My father is a very very conservative person. I always jested that he only once had a new idea, leaving his moms womb, and even regretted that idea. Ofc never when he hears it:D
He is very emotionally detached. His life is like this every day: He wakes up, eats goes to work, comes home, eats, reads the paper, watches the news, a little more tv and then off to bed. Basicly no interactions with anyone in the family.
My stepmom, never ever hid the fact that neither my sister nor I was her not her real children, and favored her own son (lill'bro) openly.
Since my bro learned to walk, my mom seems to have had the idea that I learned how to trip him. Everything that went wrong was my fault even if I wasnt in the room, and my brother wasnt slow to make full use of this either.
I knew before I was 10 that I would get kicked out of the house by the time I hit 18. I was told that I was a necessety for having a normal life for my mom.
Me and my sister was pretty much not allowed anywhere in the house but our rooms, and the kitchen only when we were eating.
Just scetching out the plotline there, wont go any closer as that stings a lot still.

Life was very hard, couldnt get to talk to my dad since I knew the repricautions would be severe, and I knew that his actions would be in vain since he didnt believe anything we told him.

To my parents outward appearances mattered more than anything. I remember once being beaten up, I got scolded that me being in a fight gave a bad reflection on my dad and mom. No mention of me being blue and green, just how it reflected on them.

On the outside the family "looks" normal. Most people even within the near family have no clue what have happend. Both my sister and I have problems these days and talk about it alot, but both fear ever having to talk about it with our parents.

I know that I have been developing a depression since I was about 12. All the signs when looked back upon begin there, and I have a hard time coming to terms with half of what happend. Mostly just trying to ignore them as mere fiction as I doubt a family could have been that detached to reality.
But the more I am delving into my past the worse I feel about it all.
I have professional guidings in this and as mentioned have been asked to confront the past with my parents.

Im not sure I can, or even how to, and I ask for a little help here where I am happily a little anonymous