S.L.
I don't have many suggestions for you, but I've been going through the same thing lately. I'm also nursing a little one, and I have no desire to take meds now. I find myself having 'off' days; getting frustrated by my husband's lack of family time; and wondering if this is all there is (and if I'm supposed to be enjoying it more!). So yeah, I know it's there, lurking beneath the surface.
I've been considering sun lights. What kind do you have? Some of them aren't very impressive/effective, so make sure you have good ones. That said, I've never used them at all. My depression in the past was a year-round event. :P
I also stay involved. I do things outside the house almost every day. This never used to bother me, but with a little one, I'd go crazy if I just stayed home all day. So we go to a playgroup, some other children's place, or just out to eat. Honestly, taking care of DS is what keeps me going. I'm sure I'd be in much worse shape if he weren't here, needing me all the time.
If you're an AP/crunchy type ;) there are definitely many moms in the Indy area. (For that matter, if you're not the crunchy type, I'm sure there are plenty of those meeting too - LOL). I'm too far away for most Indy stuff - I just go there once in a while for shopping, zoo, and good Mexican food. ;)
Keep your head up...
S.