How do I come out as trans to my parents?

I've always sort of rejected anything that would make me seem female and in the past few years, I've gone from rejecting those outside forces to rejecting my biological sex altogether. I know I am much happier when I'm acting like a guy, being called a guy, or when people call me by the name I chose for myself, but I'm afraid to actually tell my parents how I feel. My friends I can deal with and I can figure out my school later, but this is urgent.

Now, this is where I sound stupid. I've come out as bisexual to them and even told them that I was (before fully accepting that I feel like a man) genderfluid. However, they never really acted on that and neither of my parents refer to me as a man despite telling them I would identify as that. I've never felt able to talk to my parents so I feel really terrified, especially since I really want to start hormone therapy and at some point (not for a while) get the surgeries. And, yes, I've done some research and I'm still doing more.

My biggest fear is that they won't even try to call me by my preferred gender. I'd understand if they slip up and forget sometimes but I'm genuinely afraid that they'll not even try and they'll tell me I'm just exaggerating or this is just a phase. I know it's not and I've felt this way for a while, and I've even told my girlfriend about it but my parents are different because if I lose my parents, I will never be able to get over that.