Hello friend! If you want someone who's been in your situation, I am one of them. Long story short, I used to work in collections in a call center and it happened a few times that the client would poke fun at the way I spoke or told me to slow down (I am a mild stutterer, struggle with "vomiting" my sentences, repeating certain words (kinda like Jimmy Two Times), not articulating enough, etc...). But honestly, the vast majority of people just did not give a shit about it. Ultimately they expect of you to offer, well, a good service. I think you'd be surprised at how much people will forgive you if you show interest, good faith and offer an overall good service to your clients. The people who mock you probably have low self esteems and are not well with themselves, that's why they project this negativity onto you. It's corny, I know, but it's true! I would advise you to take your job seriously, but not yourself! If you stutter mid sentence, or didn't speak correctly, just take a deep breath and take the time to say it again in a better way. Don't hesitate to poke fun at yourself when doing so, it's actually a power move! I am at the point where, if I stutter, I'll most likely giggle and over-articulate the word/words that I stuttered on. It lightens the atmosphere, lowers the tension & shows that you ultimately care about having your message come across correctly. If you need any clarifications, help, friendly advice or whatever, my DMs are always open. Keep your head up! :)