maybe it will help to write a super quick draft on paper then do it on the computer the next day or later honestly for me writting what most people call a quick 5 minute email never takes 5 minutes getting into my office and setting a place on my desk for the laptop takes some time cause my office is a terrible mess  turning the computer on and waiting for it to actually power on finding the right email adress to send to and then the longest part of the task is actually writing the damn thing i back space again and again get stuck on how i want to word something words are hard proofreading for errors and ive found that going into the task with a prepared rough draft no matter how simple the email and how others might think its silly to need gives me a little confidence makes me feel like the task is mostly done i also find its less pressure to write the message on paper cause i dont have to actually hit send if im in the email doc i feel i cant back out and have to commit to making the perfect email which stresses me the fuck out   idk it doesnt always work for me but sometimes it really does i hope this helped im sorry you are going through this its a really rough feeling but dont beat yourself up about it because it truly isnt your fault