Hi L.,
It's all in the attitude. If you dread going back, it will be awful and you'll resent all the time away, life will be miserable, etc. But, if you decide that this is what needs to be done (for whatever your reasons are) and that you might as well enjoy your time at work, you will.
Sounds simplistic, I know, but I've seen the truth of it in the 15 years I've been a working mom. Those who really want to be home would make themselves miserable and those who didn't mind the work or wanted to work, made it work for themselves and their families.
I never aspired to be an SAHM. Here are some things that helped me...
1) I started the transition back to work a week or two, sometimes a month early. I would spend time away from my kids in increasing increments, so everyone got used to it.
2) I established workable routines and stuck to them. This made mornings and evenings as low stress as possible and gave me the most time for just enjoying my kids.
3) I made sure that when I was with my kids, I was WITH them. My focus was on them, not the laundry, the dusting, the cooking, etc. My husband and I found a handful of 30 minute, start to table, dinners and decided we could live with a house that was always a little messy so we could maximize our time together.
4) I refused to give in to guilt, melodrama or regrets. I was living the life I chose and I was happy with my choices. Since I was happy, everyone was happy.
Last but not least, I would strongly encourage you to realize and accept that your husband may do his "parent gig" differently than you. That doesn't make it wrong! Stay focused on the important things: is baby getting enough food, enough sleep, changed regularly? If the answer is yes, don't sweat the small stuff. Since your husband is the one at home, he needs to make it work for him and the baby, not you. I share this only because I've seen many of my friends wind up in marital counseling or divorced because dad's parenting style was not what mom could handle while she was at work. At no time were the children neglected or abused, but since it wasn't "mama's way," my friends flipped. Some healthy discussion on parenting philosophy and how to execute that philosophy would be wise (if you haven't already done so).
Whatever you choose to do, do so wholeheartedly. Good luck.