Okay girl, please feel free to message me anytime, I am always here to support you!
I completely understand you, my mom told me the same exact thing your mom said, and more than once. I still think she would rather have me die, then have their family know about me transitioning, because she is very ashamed of me, and you need to understand that your family is not that good, and that they are not meant to be perfect. Don't do something stupid because of them, I know you might feel alone, and everything, but you can always build your own family.
About the childhood stole from you, It's something we all go through, and I hate it when older trans folks, say that we younger ones should not feel that, because we got it luckier than them or something, because we are all in the same thing, some people got more or less years they regret, but also at that age we couldn't have done anything, so it's even worst, and you wish your parents would have picked up the hints, instead of suppressing us. You just need to think about the future, you can't do anything about the past.
Also, I'm 18 and I'm in high school (last year), but it's really hard to be trans in public, in fact I don't do that, and I'm still in the closet, because of my family, but kids can be really mean, trans teen or kids get it really hard too.
Also, your mom needs to more time to come around, maybe with time she will, and it sounds like she regretted herself already.
Good luck on your journey!