How do you write an effective coming out message?

Hi all. Planning on coming out to my mom via text message while I'm at my dads for the weekend. There's a chance I chicken out, but assuming I don't, how do you effectively write a coming out message? I feel like it has to be short, concise, and straight to the point, but doing that almost makes it feel scarier. I've been thinking something like

"Hi mom.

I'm trans. I've been struggling with this since March 2025 and have been trying to build up the courage to tell you. This is part, if not completely why I've been struggling so much mentally over the past year. We can talk about it more, and I'll answer any questions you have. I just don't want to overwhelm you in one message. Take any time you need to think about it. I'm not asking you to understand, but I am asking you to support me."

Should I be starting a conversation before saying this? Is this message okay? Constructive criticism is more than welcome!

Thank you!