To stop stuttering when saying your name you have to practice that, the rest I'm not sure, don't be so hard on yourself, your bioligy predisposes you to get triggered by the events you mentioned, I know I sound like a broken record recommending this to everyone but one thing that helped me was singing, try to start singing your troublesome words along with real songs too, sing songs correctly following their lyrics and repeat then when you're free at night, go out to order food at a restaurant, speak with your belly, say um... and if you want to stutter clench your teeth and say the word from the side of your mouth, just tips, repeat until you can confidently order without feeling shame, you have 2 things to deal with from my observation. One is your shame, as a stutterer myself I get it, it can be embarassing but there's little to do but be yourself, you're a stammerer, own it, stutter and don't give a fuck, yeah, get stares, get mocked but it's better to do it scared and mocked than not do it and still be laughed and mocked. Two, fix your anxiety, those experiences have made you start going into flight or fright mode to avoid stuttering, that's not living man, it's not that you are just scared you're now actively trying to avoid anything that might end up in a bad way. As a stammerer you need to build the mindset of "if everything goes wrong, I'll still be fine.". Your gap year you could explain it away as volunteering at a family business, hospice etc.. Or just say covid, don't sweat it.