I, too, also agree with the other comments of contacting your physician to be checked for post-partum depression. I was diagnosed last year several months after I had my second son. To be quite honest, I should've been treated with my first son, but, I was too afraid and ashamed to admit this. Anyway, I read Brooke Shields book, "Down Came the Rain". It encouraged me to go seek help. I'm so glad I did.
If you have a support system (i.e. family, church, friends...etc), I totally recommend tapping into them as a resource for helping you during this time. Just remember, it's only for a season and that means it won't last forever. ;0) And, it is so ok to ask and get help.
You may not feel this way, but, you're an admirable and amazing mom. Keep up the good work and keep, keeping on.
Many Blessings to you,
L.