I'm a guy, so I don't know postpartum depression, but I do know OCD. JGF25 is right in that a lot of women get hit by OCD after childbirth. What exactly are you obsessing about? Have you felt this way in the past, or is it a new sensation?
And don't worry about being hospitalized. OCD can be treated without coming anywhere near a hospital. We are here to help.
Have you contacted a psychologist? It is not unusual for women to have postpartum depression. The key is to tell someone and get some help. It doesn't necessarily mean you will be hospitalized.