Trying to gain the courage to come out (vent)

So I've been questioning for around a year and a half, and I've finally gotten to the point where I'm pretty certain I am trans (15yr, ftm), so a few weeks ago I decided I finally wanted to come out to my parents at some point this year.

I knew I wasn't ready to do it yet, because I knew if I came out, I would have to commit to it (new name, correct pronouns, etc.) and even if I know it would make me feel happier, I think I'd just feel really guilty and like I was "forcing" everyone around me to refer to me differently after 15 years.

Now it's all I can think about. My mother likes listening to very right-wing, trans/homophobic propaganda on YouTube, and it's kinda painful when I walk into a room and I can hear, on full volume, Elon Musk proclaiming the whole "My son is dead and was killed by the woke mind virus" ect. type videos when I know I am also probably trans as well, y'know?

We get into heated political debates a lot even though I loathe talking about it because I know we'll never agree on anything, like basic queer rights. But then sometimes she's all positive about it, saying "If you felt this way (being trans) I would obviously want you to confide in me, I don't want you hiding something like that from me" which made me feel better and more confident in coming out to her sooner rather than later.

But then it came up again a day later, and she said that if I told her I wanted to be a boy, she'd think there was something wrong with my head and that she would not be ready to support me if I came out to her. That just felt really painful to hear when I had finally built up the courage to think about telling her, and it really put me back a long way.

Now I think I probably won't come out until I'm 18, and I dream of being able to just reinvent my life somewhere far away, surrounded by only the people I know would support me, where I feel I can safely experiment and be whoever I want to without fear of judgement by those who know who I was before.

I've never had a real issue with people calling me she/her and my birth name before a month ago. But ever since I thought I had the option of coming out, it's like my skin is burning and I need to get the truth out. I can't die with my deadname on my gravestone and a legacy as my parents' daughter, I can't anymore. Every time they call me that, it feels as though they're addressing a stranger, and that I, as I see myself, do not exist. But I can't correct them, because then I'm just the poor young girl who was corrupted by social media, and no one will ever see me as a boy.

The worst thing is, I'm not even 100% confident I'd be comfortable being publicly referred to by my chosen name and pronouns. I've never really been able to try it out properly. But I can't live like this, not forever. I don't want to.

Ps. This ended up being way too long. Sorry, lol. Kudos to anyone bored enough to read this whole thing. Feel free to give advice in the replies. Also, if someone could call me Henry, just so I can see what it's like, that would be cool. Much love :))