I am on Zoloft and have been for 8 years which means I had all my kids on it. They are all fine (Jake's death was a vaccine reaction) , happy and never had any b/f problems. I take 50mg and it has been a life saver during N's pregnancy although I cried every time I went to the ob/gyn. Make sure you get your thyroid levels checked. I take 75 micrograms of thyroid meds and have been feeling worse as well lately. My doctor confirmed that the thyroid can go belly up during any time you are pregnant and that can most definitely result in depression and the like.
I am feeling fine (cranky and impatient) but ok. So everyone out there suffering: My personal opinion is that it is better to take some meds then to feel so terrible all day that you can not take care of yourself and your kids.
Hang in there.
Get your thyroid checked.
Talk to your doctor about meds.
Sending my love!