I'm very sorry to hear about this, bro. I completely understand your pain and frustration, and I hope that they'll eventually come around with time. They're deliberately hurting you, and that is not okay. Though from their perspective, the person they thought they knew is someone else, and they're afraid of losing tnat person but really they're in denial. Even open-minded parents aren't always on board initially, and even when they are, sometimes they'll occasionally misgender out of habit. A lot of cis people have a hard time understanding what we go through; so I suggest dumbing down explanations if possible. Right now, you're going to have to rely on your inner strength, to keep you from completely breaking down. Emotional support from your family would be awesome, I'm sure, and your family shows promise based off of similar stories I've heard. However, regardless of what they believe, you're still a man and you know that. Your validation matters more than anyone else's. I hope things get better soon, bro.