I’m sorry for what you’re going through. It hurts enough when strangers, people who we don’t even know or care about, make fun of our stutter. It hurts much more when it’s someone we love and care about. As you grow older there’s one thing everyone starts to slowly realize, the adults in our life, such as our parents, are in fact human beings and can do shitty things as well as make bad decisions. How you felt and feel is valid. My advice to you would be to learn to forgive. If you let it the pain will stay with you for a long time and perhaps even fester. People make mistakes and do bad things. It sucks but such is life. I spent a long time hoping, wishing, and praying that my stutter would go away. It took me a long time to make really make peace with it and not let bad interactions stick with me. It isn’t easy but in long run it was the right decision for my mental health. I hope you feel better soon!