i don't think i'll be able to come out until my parents die

i'm 21, and i've been questioning for five years, and at this point i'm pretty sure i'm trans. i live in texas, and i'm scared. i don't want to move, this city is my home, and i love my family so much, but they just don't understand what it's like. they're conservative and christian, and they think their way of life is the only "right" way, and that everybody else is "wrong". my sister used to be liberal, but over the past three years she's gotten more and more conservative, and now she's just as conservative as my parents. i'm scared it's going to happen to me too. my family has no idea that i'm left-wing, i try to avoid getting into conversations about politics with them, but i think they might think i'm a lesbian, because i've been getting my hair cut short for a few years and i've never been in a relationship or shown much interest in men. i dress somewhat androgynous, i don't have much dysphoria so i'm ok with dressing more feminine, but i definitely feel more myself when i dress masculine. i just don't know how long i'll be able to keep this up. i worry that as i get older, my family may start asking me questions about politics, and i don't like lying to them but i also don't want to get shunned because i'm liberal. i also worry that i won't be able to find a partner that's understanding and willing to lie to my parents for me. i've thought about moving to a more trans-friendly state, but even then i don't think i'd be able to medically transition because my parents would want to spend time with me over the holidays, and i don't want to get disowned for being trans. they are very stubborn, i don't think i'll ever get them to see my perspective, and i just feel like i won't ever be able to truly be myself until they're dead. but i don't know if i can last that long. i worry i'll forget, since i'm not able to do anything about it, and that i'll become depressed, or brainwashed, or both. i just feel pretty hopeless right now, and i don't know what to do.