[marilyna]

Lexie,
I'm so sorry you're going through this. I haven't experienced this with my 2 babies, but had a couple of thoughts.
One is that it's probably natural to feel blue when having to leave the baby to work. I think I would feel that, too.
Another thing is probably the lack of sleep. I know what I do is frowned on by a lot of people, but I have a 9 month old and a 19 month old and I get 8 hours of sleep every single night and have almost the entire time I've had them. Except the first few months with the oldest, before I learned this.
I sleep with my babies. Now the oldest one usually sleeps by himself til the wee hours of the night, then I go get him when he wakes up. The 9 month old always sleeps with me. I don't get up to feed her if she wakes up. I just feed her right in bed and she goes right back to sleep.

HTH