I had a similar experience for over a year in a position. I had a bit of stuttering too. However, later I realized they were mostly just very stupid... Really bad, I still have a kind of trauma even though I've been out of there for six months. So at first I thought it was a mix of me not being able to unblock myself and them being very united, but in the end I realized that they were just horrible lol I even had to endure some jokes about my stuttering, in addition to hearing homophobic and sexist teasing all day long! My advice if you think you might be in this kind of situation is to force yourself to put all the energy you can into changing positions. If you think I'm exaggerating or that your case isn't comparable to mine, then don't worry, time will do its work and you'll grow closer. After-work events can help!