My heart just breaks for you and S13. I don't understand this stupid "affair fog" to begin with. But, the children suffer enough, why won't she just let you have time with him? How do the kids fit into the fog? Especially because the biological father dropped the ball, wouldn't she be grateful that you want to be there for him? I just don't get it.
So, IMHO, I would get all the paperwork ready to go. Be prepared to file for custody. But, wait to see when and how she responds to your texts. She seems like she lets her emotions get the best of her (I did that too - working on it). Maybe she is trying to think about it before she responds. You came off a decent day Sunday, maybe, just maybe she will respond appropriately.
Sending you strength and prayers...keep us posted.
M 44 H 46 M 20yrs T 25 yrs S15 S12
ILYBINILWY 7/18/15 Move to MBR 9/8/15 Physical Separation 10/10/15 Suspect A 8/2015 Confirm A 12/27/15 D filed by H 2/2/16