I can absolutely relate to you here. Back in my pre-T days, self injury became so usual for me I ended doing pretty bad things to my body. Let alone suicide attempts (four as I remember, all of them failed because my body is too resistent)
And, being a Neet, after being 4 years without leaving my room at all, I ran out home that day to get my shot done. And I said to the nurse "good morning

" and "thank you" I fainted in the hospital twice lol but that didn't stop me from getting it.
Things just got better from there. I'm still sociophobic but I can endure to go shopping in a mall and walking in a street full of people for a while without panicking, even if I know I'm not passing 100% and I get she'd sometimes.
Just think of it this way. You're stuck in the dark hallway. You got up from bed because you were so thirsty you couldn't sleep. So you went to the kitchen for water but stopped in the hallway because it's so darn dark you're afraid to continue. Well, at this point, you can't go back, because you know you're not gonna be able to sleep being so thirsty, and you can't stay standing there forever. You surely had an experience like this when you were pretty young, right? What is the best to do when you're chickened out in front of a dark straight way?
Just close your fist, tight your teeth, and RUN STRAIGHT FOWARD!!!! You will have arrived before you notice!