Yes to the legal advice.
No to the leaving - could be used against you as "abandoning the child"...
With his attitude, I suspect you want to do everything to fix this. That's normal. Completely.
The sooner you realize you can't fix him, the bettr you will be.
YOU DID NOT CAUSE THE AFFAIR.
IT IS NOT YOUR FAULT.
Read the 180 in the healing library.
Keep in mind, the 180 is about you and healing you alone.
It is not about getting you H to do anything - it is not a manipulative tool.
It sounds whack. It sounds counter-intuitive. I know.
But it is the #1 best thing you can do for yourself right now.
He is not in any way close to remorseful - you can't fix him!
So, take care of you & the dear baby.
Sending you strength.