Seperation Anxiety

My daughter is 7 months old and I have been a stay at home mom since the day she was born. I am ready to go back to work but I can't seem to let go and let her out of my sight. I have it set in my mind that nobody knows her better then I do and nobody is able to take better care of her then myself. I am a first time mom so im not sure if it's because I don't want to miss out on the moments of her first year or if it's just because she's never been out of my sight. The only person she stays with is my mom because I am completely trustworthy of her. I am afraid my seperation anxiety is never going to end and that's it's going to ruin relationships with her family. Am I being selfish or is it normal?