Mommy guilt

So today John and I took Olivia over to Kindercare to get her all registered and find out what we need to know about having her go to daycare. I thought I'd be more emotional, but I'm really just excited. Not about being away from her, I know that'll be hard, but I think she's gonna have so much fun--playing with other babies and getting new experiences. I feel weird about having a child. My friends are all mourning their children growing up, lamenting the fact that their babies aren't....well...BABIES anymore. I'm not like that. Every day that Olivia grows and learns something new brings me joy! I love seeing that. I'm EXCITED about her walking and talking and playing and going to school. I can't wait till she can come home and tell me what fun thing she did or a new friend she made! I'm also excited for me--starting a Big Girl job and helping bring more money into our family. I put something to that effect on Facebook and several of my friends commented. One said that she would PREFER to stay at home with her baby, but couldn't and "to each their own". Another posted how she HATED when she had to go to work and be separated from her kids. I know I'll feel that way too--Olivia has been with me all day, every day for her entire LIFE! I'll still be her mommy, but it's not going to be the same for either of us. I know this is best for us, but I still feel so guilty. I need to work--it's a good opportunity for Olivia to socialize with other people and babies her age and learn new things. It's good for me because it'll get me OUT OF THIS HOUSE! I feel like I'm going CRAZY being stuck here all day! I never get to talk to anybody. I cling to John and my mom like a lifeboat in the middle of an ocean in the middle of a hurricane. I need to be around people. I need to feel useful and make money and give things to my daughter that I wanted and didn't get to have. We could make it by on John's salary, but with me working too, we'll be making LITERALLY twice the money! I won't get to spend as much time with Olivia, but I won't be as depressed all the time and the time I do get to spend with her will be better--I'll be happier, John will be less stressed about money, we'll get to take trips as a family to the beach and to New Orleans and to England with my mom. So...why do I feel guilty? I feel like I'm being a bad mother by being happy and excited about the new possibilities that are opening for our family now. I feel like....I feel like I should HATE having to do this and I just....don't.... And that makes me feel worst of all.....