Teachers need to start recognizing speech impediments. There's no optional thing in hand. They **NEED TO** recognize it because I know so many friends who had speech impediments, who have ended their lives because they felt like they were going to be failures when they went out to the real world. I recommend you, the first day of class, and before ANY activity that involves speaking, let your teachers know, whether it's by talking to them before class, making a note on your phone and showing it to them, or sending them an email, and it does not matter if you annoy them or what, because they are there to teach you. If they try to make you do it any way, walk out that class. You should be practicing your speech in a environment where you are comfortable. I'm so sorry that you had to go through all of that and I wish you the best. I know that there's genuinely nothing I can do to help you but all I want to say it to try easy onset, and learn as many strategies as you can to control your speech because your message matters just as much as the teacher's.