S.B.
I went back to work after my divorce. It was tough, I won't lie. But, I didn't see it as abandoning my children. I was PROVIDING for them. I had no choice. I was very fortunate in that I had a daycare provider who treated my son just like one of her own kids. My daughter, 10 years older, was fine on her own and welcome at the daycare too. I didn't get charged for her since she helped out a lot with the other kids.
I kicked butt at work and my kids were really proud of me. I really focused on feeling good about myself and being able to provide for my children. The first few weeks is the hardest. But you'll get into a routine and I really believe things will be okay. Don't guilt yourself because it was one way for one kid and different for the other. You are very fortunate to have a job and I think you should let it build you up in your esteem so that you can, believe it or not, be an even better mother. Your little one will miss you too, but it's perfectly okay for him to have his own little social life and experiences.
My kids turned out to be really well rounded and good individuals.
My youngest, my son, often has dinner cooking for us when I get home from work. He's 15 and incredibly responsible. He has never once given me a guilt trip. In this day and age, married or not, many moms work. We really make the most of the time we have in the evenings and on the weekends to cut up, be silly, watch movies, go on walks. He's in high school now so his days are pretty busy too. We are very close. He still adores his mom more than anybody.
It will take some time. My advice is to do the absolute best job you can when you're at work and then be the absolute best mom you can be when you're at home. No one's perfect, but our kids don't expect that from us even if we expect it from ourselves.
You and your kids will be just fine. You really will.
Best wishes.