Klopper, I've never taken Parnate. However, I do know it's considered to be a very effective treatment for SAD.
It's also a last resort treatment, as MAOIs present a lot of problems regarding interactions, both with foodstuffs and other medications which can be fatal - the list is long, and it includes very common OTC substances such as allergy mds, as well as certain supplements. The list was updated a couple of years ago, as it was a little bit too stringent, but it's still very daunting.
Your doc definitely needs to asses your situation very carefully before prescribing. You should also let your doc know about any meds you are currently taking, as there is a mandatory washout period in between terminating SSRI treatment and starting MAOIs.
Although I'd never even consider taken an MAOI, I do know that SAD is a debilitating and highly taxing condition, as I used to suffer from it.
Have you done CBT? That's the only thing that ever worked for me - great results, by the way, as my anxiety disorders have been in remission (cured, as far as I'm concerned) for over 5 years.
Good luck.