There are some helpful tips on the D-MER website. I don't think that would help with ppd but it may give you a little more peace.
IMO, I don't believe nursing causes ppd. If you feel that the nursing agitates it more it is because there's the combo of the dmer.
I personally would seek out to a professional and see if therapy and guidance would help you. Because if you stop and still don't get better it will be too late to turn back, Kwim?
Doctors usually tell moms to stop if meds are needed because they don't want it going over to the baby. I am No professional but I am a strong believer in trying alternatives first.
Never mind the typos. My "smart" phone is a high school drop out..