Hi, I'm currently at college and have the same problem there at the start of each semester. Personally I see positives in it as it lets everyone know I stammer and a lot of the nerves are gone after that. One other thing you could do is email your teachers and let them know that you have a stammer and feel nervous about introducing yourself. I have done this a few times in college when we had timed speeches etc. and knew I would not really be able to take part. I think your teachers would be very understanding and could help you.