back to work..

So I have to go back to work in 2 weeks... I am feeling very sad about it, I don't want to leave my baby but my husband and I both need to work. But I also don't want to abbandon my career, I worked very hard in school and for the past 10 years and I have a pretty good job.. my baby will be staying with my mother while I am at work, and she is very happy about it but I still feel all kinds of guilty, and when people ask if I am going to stay home with the baby they make me feel guilty even more... my MIL especially... she has always been a stay at home mom, and now grandmom and she thinks that me going to work it's selfish.. anybody else is in this situation? M I a bad mother for needeing/wanting to work? This is honestly keeping me up at night and I don't know what to do.. help!