I'm no expert, but this sounds more like POSTPARTUM DEPRESSION than OCD ... Of course, it could be a combination of the two ... Regardless, I can't express how important it is for you to get professional help for this RIGHT NOW. This forum simply cannot provide you with the kind of help you need at this moment.

You say you can't see a psychiatrist because you're at home with a newborn ... For God's sake have the psychiatrist come to you then ... If you can't or won't do this, then at least have a trusted friend or relative with you 24-7 to protect the life of you and your child.