You can do this OP.
I was working thankfully in an admin/ pr / practical support at the time. At home one Sunday afternoon, I dozed in front of the tv and woke up with barely a squeak that could be understood. Every word I tried to say even short ones, my speech broke before I could get a word out esp if 2 syllables or more.
I pre-wrote a series of texts to send to people. The initial ones said I had laryngitis (which was confirmed by the GP, however, my only symptom was lack of voice, no inflammation and best of all no pain) and explained that while I was happy to receive longer texts that I currently was resting as much as possible and would reply when I was able to.
It started on a Sunday and I saw a GP on the following Tues morning, it made me a better listening and I used a lot of hand signals. I worked through the time as well, on that Monday once everyone had stopped teasing me about "how they had never seen me so quiet" lol.
I went to visit my mum as couldn't speak to her on phone for obvious reasons and it was then she chooses to reveal definitely laryngitis as the same thing happened her when she was approx that age. She had lost her voice numerous times the shortest being a week and the longest 11 months. My bout of laryngitis lasted 100+ days.
I have had it once since but wasn't true laryngitis, it was caused by me trying to ignore vocal cord strains after aspiration of vom into my lungs and not dealing with it, so I had an almighty lung infection as well with vocal cords which were soaked in acid
You will not be strange with pre-written texts, or a notebook and pen. Get others email addresses and numbers so questions like after the S.A.L.T appointment can be forwarded on to them.
Good luck, if I think of more I will come back to this thread