I know what crippling loneliness is, nothing can alleviate it truly, nothing other than true presence and caring, and if you're sexual, then also true sexual intimacy. Without one of these, everything seems either unbearable or not worth solving.
I can't imagine the pains of a person who's mtf, let alone mtf *and* struggling with connecting and also with physical conditions aggravating social interaction even more... but humans are very strong beings and they can transcend tremendous difficulties...
From my experience I know that there's no way around the need for genuine human connection, so a way to rise above the drowning line would be to invest yourself in untying the knots that you have there. Exhaust the possibilities that you can see, and then find some more, less obvious, ways of trying to connect. And definitely connect with yourself. Looking inside yourself in reach for understanding love you'll discover many solutions to other (seemingly unrelated) issues.
I can see how living with the parents is daunting... and the fact that in the moment you can't see that changing must be terrifying, but things do change. Tomorrow you'll know more than today, tomorrow you may find natural to do things that now seem alien to you, the current situation will shift.
All one can do is to do the maximum they can with what they have and what they know in the moment. Try to find out what is the maximum that you can do now.
How is your voice progressing?
P.S. But if you're tired to be strong or of trying to be, let yourself cry, feel self-pity, feel anger, feel everything that a powerless person can feel, because we can indeed be powerless in some moments. The waves of strength and powerlessness come alternatively, no need to fear that you'll never feel courage again if you let yourself be lost, the courage is inevitable. Just look at how SI is pissing off people here. How people fight again and again, despite even themselves. So if you're sick of having to solve all these issues on your own, let the responsibility be not yours to bear from time to time.