OP, you are understandably stressed and worn out with all this. You have a baby due any time!
My advice would be:
- send one simple response for paper trail along the lines of:
Hello X, as you know I am at the end of the final trimester and as such I am feeling quite tired and preoccupied with preparing for the arrival of our baby. I appreciate you reaching out to me to discuss finances, however we can sort that out via the official channels of CMS.
I cannot control whether you believe this baby is yours or not, however I will remind you again that we were in an exclusive and faithful relationship and so, the baby is yours. I am happy to facilitate a DNA test in the future if necessary.
I would ask that if you do not want anything to do with your child, then you respect the boundaries I am putting in place and cease with your threats. I am concerned that you are only contacting me now at my most vulnerable to cause me emotional harm, and I feel that you are perhaps trying to take advantage of me by trying to get me to sign unofficial documents.
Again, and to be clear, I won't be contacting you again if you are not wanting to pursue contact with your child as you have stated previously. All contact will go via official channels, as said earlier. If you feel the need to instruct a solicitor, then that is your prerogative.
Thank you,
OP
THEN:
Ignore his messages and do not get sucked into his attempts to weaken you while you are already vulnerable
Do not put him on the birth certificate PLEASE it will make your life harder. Do not waver on this and do not let him know when you are going to do it!
If he wants to pursue contact, go via official channels only and don't enter into random agreements with him.
Work on strengthening yourself physically and mentally, look after yourself, don't be gentle with him as he is being savage with you and trying to get into your head.
Enjoy your baby, and do not let him sour this time.