In R since shortly after DD.
OK, That helps a lot. You are both handling this unproductively. (MHO).
You definitely need to see a Dr. And you both need MC to learn how to communicate with each other.
Most insurances pay for that either in or out of network, so check into yours, please.
PPDep. is very real, and add to that the feelings you are experiencing from your H's infidelity, a double whammy.
That does not mean he gets a pass. He needs to step up, and help you with this, all of it. He needs to understand this.
Ask your Dr's for recommendations, and you will find the right person to help you. You will know it, (there are some idiots out there!)
Your children and baby need you, all of you, and you sound to me like you just need a little help and guidance getting back to a good place, and him too.
He needs to quit the self pity party, he brought this on your family. Now he needs to step up and work his tail off to make you feel safe in your marriage.
(Side note, My fwh still feels like crap for what he did to us, but he works so hard to make me safe and trusting towards him. He saves the pity (guilt) for him, not me.) At some point, they need to forgive themselves, but we are to be their first concerns.
Discovered what was right in front of him and nearly lost.
Always, tell the other BS! Always!
"It's hard to be in love when you can't tell lies"!