Airy Sound - Saxophone

by Nick
(Texas)

I have been playing alto sax for a few years now. In all my 4 years of playing saxophone, my saxophone has never done this before. It started doing this a few days ago. Whenever I try playing it, it makes this weird airy sound. Like something is blocking the air. It's becoming very difficult to play. The sound is not clear anymore. I've tried different reeds and they all do the same thing. I've checked my mouthpiece, and it's fine. I've also tried positioning the neck differently and that still does not help. What is wrong with it? I'm trying to figure this out. I cleaned it and everything but I can't tell what is wrong with it.