Emy,
you have a few options. You can certainly change your status to that of a student (you must speak with the school first - and they usually have very good international student counselors). You can also transfer your H1b visa to another company, if that is available.
There may be other options, depending on your particular situation, especially if you want to continue working. Remember that as a student you will not be able to work, but generally, after your master's program concludes, you would be eligible for OPT (a one year work permit).
I hope this information is useful. Remember, this is not legal advise, but just general information. I would be happy to speak with you if you have other questions.
Renata Calderaro, Esq.
rcalderaro@visamiami.com