I think you have a few options just based on what you think will give you the most closure. You could go cold turkey, accept things aren’t going to be beautiful and perfect and focus on your family without putting in anymore effort. My second suggestion is to say something along the lines of “this really has bothered me and it’s something that hasn’t changed and because of that I have to take care of myself so if you’d like to be a part of my life and would be willing to change great if not let’s stop communication.” In whatever way makes you feel best (text, call, etc.) or third something like “I’d love to have you in my family’s life if this can change, can you agree to do that?” I’ve had quite the rocky relationship with my parents so I can understand where you’re coming from. If you want someone to vent to or someone to compare stories with please feel free to message me. Most importantly please remember that you don’t owe them anything. Giving life to someone does not eternally indebt them to you. Do what’s best for you and your family. Best wishes!!