I would do a lot of practicing with people you don't know; chat with the grocery store clerk (tell her your problem) and others like that. I'd go out each day and find someone to talk to (library check out people are good or reference librarians even better, go ask for help "searching" for something -- maybe materials about public speaking? If you can share your problem it might not make you feel so alone.

I think were I, at this time in my life, to hear laughter, I'd look in that direction and say something out loud like, "I hope that was supportive, nervous laughter?" and kind of chuckle myself. Ignoring things does not make them go away or help with them. I'd pretend my problems doing presentations were a monster in a dream chasing me and turn around and address it head on (if you get to pick your topics for your presentations, "make up" a dream and translate it?). I don't know anyone who actually had the thing chasing them in a dream catch them? But I do know people who confronted it and had it go away. Maybe write a story about conquering your problem?

Another thought, can you go to your teacher and share your problem and ask for her advice/help? I had trouble when I was taking French in high school, in the language lab, I was nervous and couldn't remember a thing in my head because I knew the teacher was listening. She went out one lesson and just left the lab tech and I didn't realize it but left it tuned in to me and because she had left I did much better at listening and following/responding. When she came back, because the mike had accidentally be left on I heard her and the tech discussing me and how much better I was doing as a result of the teacher leaving. That made a good connection in me that the teacher was trying to help (as opposed to being "out to get me" :-) I wasn't quite as scared after that. Talk to your teacher and, depending on her response, you might feel better and less pressure?