I know that feeling so well. My spine would hurt from my epidural spot. It stressed me out. The poor kid had colic as well.
Baby 2 came and I spiraled. She cried all the time and I knew it was from the stress I was feeling. When she was sleeping I was either taking care of my son or throwing up.
I think it started tapering off around 4 months. I always had anxiety as a part of my parenting when the kids were young. I think its a person to person thing.
I wish I would have had more help then I did. My normal doctor gave me anti depression med. What I really needed was a therapist. I needed someone other then friends to talk to. I am also bipolar, I had no idea. So I suggest to go to your doctor. Make sure there is no under line problem. See a therapist and try to find some mommy time just for you.