I'm very sorry this happened to you. I hope you find a better job with an understanding manager. Something I just started doing this year (I'm 35 btw) is that I tell people that I stutter during the interview. Stuttering is also technically a disability (in the USA at least) so I also mark on job applications that I am disabled. This is something my SLP suggested even though I only have a moderate stutter. Sometimes people just don't know what's going on so they assume things. Letting your employer know that you are technically disabled also gives you legal recourse and employers are not allowed to turn you away because of a disability. I hope this information helps you and remember you are an amazing person and do not let anyone make you think otherwise!