I'm sorry to hear your stuttering affects you like this. If you can. I'd try speech therapy if it's available in your country. I've been stuttering since I was 4 yrs old so I can only imagine who it must be when you develop one when you're older. As for anxiety, try some meditation and also camomile tea to ease the tension. It might not work for everyone but its a try. A big tip I can give you is when you do stutter, locate on your body where you feel the tension the most, is it your throat, your jaw, your tongue, etc. Once you found the spot, try to relax those muscles and ease into the word instead out right spouting them. Hope this helps, good luck. Also trying breathing exercises because I realized that most stutterers talk from the chest instead of the stomach where most people usually do. But again it'll take some practice as I struggle with doing this but try from time to time.