Wanting off the rollercoaster

Again it's been a while since I checked in here. It's been a bit of a rollercoaster lately. Last month I switched from Cymbalta to Zoloft since I had heard from several different sources that Zoloft is safe with pregnancy and I have strong aspirations to be a Mother. The past month has been really rough transition as I am experiencing many physical symptoms (back pain, tension, nausea) and my mindset has been a rollercoaster, constantly dipping up and down. Driving me crazy (and Im sure everyone around me crazy too). At this point, I am not looking forward to anything. I feel like physical crap- and I feel lost for an answer. Should I remain on Zoloft? Should I not be on anything? I really don't know. I am continuing to go to Therapy once a week and that is helping my mood improve but only on a short term basis. I know I can fight this but I am so tired. I will continue praying as I do believe God has me on earth for a reason and will help me get through this. It's such a hard fight and I want to get better so I can help others in the future.