R20 I am so sorry you grew up with an abuser as a step-parent!! What a horrible, horrible person. Just a nightmare. Wow. what a complete piece of shit. If it's any comfort, I am sure she was an unhappy and miserable person who was abused herself in childhood. Those behaviors do not speak to someone who was loved, supported and accepted in their own childhood. I bet she subconsciously knew your father was bisexual and cheating on her with men, and took out her anger about it on you.
And fuck your father for allowing this harpy witch into his son's home and life, and to enable and allow this hideous woman to relentlessly verbally abuse his son. He sounds like a lost soul. What sane mane would marry such a woman?? Maybe he felt guilt for being a homosexual and married her to torture himself??
Your father also utterly neglected to guide and raise YOU, his kid. Parenting should include discussions of sexuality, and there should be safety around that. You were deprived on all fronts and it hurts to even read about what you had to endure.
All I can say is, don't let "them" win. Get mad, and get motivated. Do you have or have you ever had a really wonderful therapist? Do you have a friend group that gives you a feeling of belonging and connection? I'm sure your wounds go very deep.
I too was neglected and verbally abused as a child, not for being gay but I just had a dysfunctional family in general. My entire family on both sides sucked except for one aunt that I have in my life who is wonderful, but even she was sort of checked out when I needed someone the most, in my teen years. I have suffered so much, but I vowed I would not let them "win" and so I have actively rejected their attempts to saddle me with low self-worth, shame and other hang-ups that would seek to deprive me of my right to live a life of purpose and joy.
There are some things you cannot control, of course; having trauma affects your executive functioning. Therefore you may have issues with focus and follow-through. You may have an attachment disorder, such as feeling nervous and clingy in relationships, or conversely, being emotionally avoidant and finding it difficult to be vulnerable. Just being good to yourself. Do not allow that woman's voice to live rent free in your head. If you have an internal critic you have to tell it to fuck off, repeatedly. while inserting a new voice that says "I love and value myself completely."
I know, "Mary!" but seriously, I really want to make sure that you are okay. I hate that you had to endure that bitch. It is really upsetting. Sending you love through the ethers. xo