your situation sounds a lot like mine when i was 18. i dropped out of school at 16, never left my house, i just played video games and had my online friends. i knew i was trans, and i was making sure people only knew me as male online. it was hard. i became overweight, unhappy, i never wanted to do anything. i didn't want people to notice me.
one day, i had enough. i did research on how to tell your parents you're trans, i looked up how i could transition where i live, what i needed, everything. when i was 18, i told my mom i was trans and wanted to start transitioning. she didn't understand, but i told her i wanted to go to this place that helped you transition, and start there. she agreed (thankfully) and it just kind of all happened super fast from there. i don't think she knew what she was getting into agreeing or how fast it was happening (to be fair, neither did i) but it turned out for the best.
when i was in my early 20s, i went back to an adult school and got my highschool diploma in a year, and i got a job. i spent the years between being 18 - 23ish doing transitioning and finding a job. i finally landed a good job, that i'm still at actually. when finding a job, i made sure to use my preferred name so going into it, i wouldn't have to deal with coming out to everyone or people knowing i'm trans. i ended up doing my full transition in a year. don't get me wrong, it was hard but if i didn't have the support and the pushing that people did, i wouldn't be here. so i will tell you, it will be worth it to make those small steps.