Irl socialization is absolutely vital and I'm smacking myself for forgetting to include it. Tbh it may have been more important than the CBT, it's just that I did it alongside coming out (got involved in queer community). And if you're transfeminine I'll also say it's especially good to make friends with other transfeminine people.
And yeah, no amount or self work will make you feel good in a bad environment, but it can be better and it can help you get out.
Also, it's important to acknowledge self hate for what it is: a cognitive distortion. Maybe it's completely unfounded, but even if there are real bad things you've done, self hate doesn't make you better, it isn't a penance, if anything it's a distraction from becoming someone you can be proud to be.