I am almost in the same situation. My son is 1 year old.
Except when I got pregnant with my son I was 145 and I got up to 215 when he was born. Breastfeeding did not help me lose weight either, I dieted like crazy last summer too but hovered around 200lbs. I breastfed for about 9 months.
I am finally in the 180's, but its been a struggle. I exercise daily and calorie count. I have a wedding to go to in the end of June that I would really like to be at least a dress size down. My stomach is disgusting, I still look pregnant and have the c-section "pouch". I'm not sure if my body will ever see a bikini again, but a size 6-8 dress would be a nice goal eventually
My ultimate goal is 140 also. I felt the best at 145, but I havnt seen 140 since junior high.
Anyway, we can do this! I am here for support also