i was in a high stress situation recently but probably not like yours.

i was prescribed zyprexa for high stress.
i too thought that the diagnosis was something else but realized it can be for many other things; however, the medication ended up being too potent,which i learned 2 months later.
If the medication is helping you i don't think it means you are definitely that diagnosis no; however, speak to the doctor to find out the indications or uses of the drug you're taking and if its only for schizophrenia.

I know the fear of having been either misdignosed or possibly treated wrongly. Second opinions always help.
I was in a tough situation which caused me to possibly be mis or overdiagnosed/medicated and am going to seek a 2nd or 3rd opinion.