I'm sorry to hear that. In this case I would say that the behaviours of your professor and teammates aren't related to your stutter but probably run deeper than that and their behaviour says a lot more about who they are than anything about your stutter. Did you/could you talk to your teammates about it and advise them of anything they can do to support you? In my case, I told the group about it from the outset, and when I described what it was/what made me stutter they were interested to learn about it and very understanding.