going back to work

really starting to get depressed and anxious about going back to work. I have one more month left and I cannot stop weeping and crying when I think about it. or even when my son and I are having a sweet moment, it's ruined by the thought that I won't be able to enjoy being home with him anymore in a month. I will be leaving my baby at 5 months old. I have no choice but to go back to work so we can afford to keep our house and our lifestyle. everyone I run into asks me if I'm "taking the year" and when I say no they say "oh that's too bad" or they pity me. it makes me feel even worse. any advice for going back? I don't want to leave my baby!