Hi J.,
This sounds exactly like deja vu. My husband and I had our first daughter back in July 07. I knew that once I had her, I had to go back to work to financially support the 3 of us. Luckily, the company I worked for at the time was very supportive and understood the needs of me being a new mommy. Unfortunately, I was laid off in October 07 which was such a bummer because I loved what I did there, but the bonus was I got to stay at home and raise my daughter for 9 months. Well, I'm back to work now full time, and although I love what I do now for my job, the commute is about a hour ride home at night. I find myself preparing to leave ahead of time so by the time 5 o'clock rolls around, I'm ready to bounce out the door. I get home around 6 pm, and I only get to see her for just a few hours before I give her a bath and put her to bed. (My husband gets home first and gives her dinner).
I guess what I would like to say is although it's very overwhelming and I feel guilty for leaving her everyday, the best I way I try to look at it is I know she's got great care during the day (she's in a daycare program with other kids her own age). It's very cute to see how she will crawl/walk over to them when I drop her off and start playing with her "friends" It gives me piece of mind that she's happy. I'm a mother, and although financially we can't afford for me to stay home, I am not only a wife but a mom and as my responsibility I need to provide for my family. Everytime I feel like I'm going to get teary eyed or feel guilty, I try to remind myself that my daughter is happy, healthy and that I'm providing for her. I'm not sure if this helps. Just remember you're a wonderful mom, and you love your son very much. Try to hang in there. Have you also considered working from home options? I'm working with the Pampered Chef and I'm able to set my own hours with that, which is nice =)
Good luck!