I wanted to check back in here as well, and tell you all that I finally talked to my ND about this issue, and did some research on my own. I have D-MER, which is a dysphoric reaction to milk letdown. I didn't associate it with nursing right away, but once I started paying attention to my bouts of anger, it was almost exclusively correlated with the cycle of frustration just before letdown that was prolonged by stress. My ND gave me some great herbs and homeopathics that worked very well for me. Rhodiola Rosea and Sepia. I've been taking them for a week now and I cannot believe the amazingly positive difference it's made in my connection to and empathy for my son, as well as my other relationships (I'm even more tolerant of my mother, which is a miracle).
I also agree with the PP who talked about how much we expect of ourselves. I wish that a multi-generational home would work for us, but we tried it and it was horrific. It's definitely not for everyone. I am still considering a communal home, possibly with another single mom, but that remains to be seen. Just thought I should check back in and share what worked for me.