J.,
When I was pregnant with our first child, I stopped all my medications. It was difficult, but I felt it was safer for our child. After he was born I went through major PPD. Still I bit the bullet and waited. Finally on his first birthday I decided it was me or him. For obvious reasons, I chose me. I stopped nursing him cold turkey. We gave him vanilla flavored soy milk (soy dream)which tastes similar to breast milk and he was fine.
Both of us did well and continue to do so.
With our second child, again I quit medications and continued after he stopped nursing.
I feel that no matter what a doctor tells me about medications and breast feeding I will never believe that there won't be some sort of problem later on with the child.
Also, my doctor put me on Lexapro; which is typically given to treat Bi-Polar disorder not depression, and I had an allergic reaction that sent me to the ER. Be careful about what your doctor gives you and find out specifically what the medicine is treating you for. You can also ask the pharmacist.
Another thing is that after having children your body and chemistry change and what once worked for you may not work again.
I strongly recommend not to take anything while nursing. Your child has been given a very good start with 16 months of nursing. Take care of yourself, quit nursing and get yourself relief. Trust me, your family will love you for it.
As the saying goes,"If mamma ain't happy, ain't nobody happy."
Best of luck.
Cheers!!!!