Well, since you asked...

DON'T FREAK OUT.

First let me say that calling this a tendonosis is putting the cart before the horse. If it is a tendonosis, the recovery is longer and the treatment more involved.

However, we have no evidence in your case that this is anything but a tendinitis at this point. And, treating it as such is the best option. Now, if 3 weeks of rest goes by and you're not significantly better, well, then we worry about a tendonosis and you go for more testing. If it is a tendonosis and we're treating it like a tendonitis, you are no worse for the wear, it just won't get better as fast as a tendinitis will.

Here's a link with more information on the matter:

http://www.physsportsmed.com/issues/2000/05_00/khan.htm

Remember, DON'T PANIC.