It's quite clear you want a child and it doesn't really matter who with.
Adoption is clearly off the table for you as you want a "biological" child. So how about surrogacy?
I'm absolutely astounded by your total lack of understanding of how the whole pregnancy and birth and child rearing works - you are pressuring women in to having your child because YOU want them, and set out that it's (kind of) a deal breaker if they won't yield.
In regards to your new women, I'd suggest just being supportive and letting her decide in her own time - your relationship doesn't sound great and you really should be helping her through this stage, everyone I've ever known has has second thoughts, including myself. Voicing your deepest darkest fears to someone is a big deal, I'd be devastated to find out it'd been posted to randoms online.
P.s People are ALWAYS allowed to change their mind. Always.