Tomorrow I'm going to Florida to visit some family and I'm honestly REALLY worried. I'm terrified someone's going to make a comment that will make me uncomfortable (because my family is pretty religious) or I'll end up outed by my siblings and oh my goodness I'm just so scared. My mom's side of the family would disown me for my sexuality, let alone my gender, and I'm not sure how my dad's side (the side I'm going to visit) would respond but I'm just so worried someone will say something offensive or something....
Just breath, I've found that the less you make something seem like a big deal, the less of a big deal it becomes.
I would recommend talking to your siblings and asking them not to say anything. It doesn't sound like a very safe environment, so you might just have to keep quiet if someone says something that makes you uncomfortable. Good luck!