I went to see my family doc this week about my depression and anxiety. She basically confirmed what I was suspecting in that it's likely postpartum depression. She prescribed a (nursing safe) anti-depressant, and wants me to come back and see her at the beginning of November to check up on the situation.
I haven't filled the script yet because I'm nervous about taking anything while I'm breastfeeding (I'm nervous about taking most things in normal situations anyway). While my doctor assures me that it's safe, I'm going to do some research of my own just to ease my mind.
At least it's a start.