They are telling you right. I would RUSHHHHHHH to your local feed store.
They will soon die if you don't. Remember to treat also non-affected birds. Treat until all symptoms clear up + a few days.
Good luck

And don't let your parents say you don't know what's going on. My mother thinks the same, but since I end up paying for everything, she deals with it. If you are on this website asking, you KNOW what's going on because hundreds of other people who know what's going on are here, talking to you.