My condition was similar when I worked in the US at the age of 20. The surrounding and people didn’t suit me at all and I couldn’t say a word. I was just feeling angry with me and my situation that made my speech worse, that made my situation worse, that made my speech worse. So I can understand you in a way. And honestly I cannot even tell you what to do to get better. I can only suggest what worked for me.. Be in the clear about what you want for yourself. It’s easier to start believing in yourself if your aim is straight. Cut out the weed, it’s just numbing you down. It’s stagnation masked as an easy way out. Again, it’s easier to believe in yourself if you prove you don’t take an easy way out. Don’t dwell on the idea that you and your life is bad. After all, of course it is. All our lifes are bad, that’s why we’re living them. If it was all easy, there would be nothing to learn thus nothing to live for. Also maybe move someplace else, change the scenery, see something new. Also I would suggest microdosing with psilocybin maybe. It did help me tremendously in making peace with myself, which in turn helped with my stutter.