Can fish oil actually replace the need for Depression medication if you have Major Depressive Disorder?

I am 11 weeks pregnant, I was on Zoloft 150mg for two years, it worked great and I switched to Wellbutrin 300mg and I am having horrible Discontinuation symptoms. I was wondering if I can just scratch the wellbutrin, ride out the symptoms and start taking Fish Oil as my primary depression reliever? I just don't want my baby to have to be grown in a medicated filled body :( I'd rather try to go the natural route without getting the full blown effects of my MDD