I agree with MT (Surprise!
) - DS2 had his own routines but he ran to a 26/7 hour day, not 24. Makes it a little harder!
Best book I ever read was How Not To Be a Perfect Mum by Libby Purves. It's basically a manual for benign neglect, I think and allowed me to enjoy the "routine-free" time with both DS1 and DS2 (not quite so easy).
Now this:
"Part of me still believes that deep down he is good, but that he has some major major problems which have got in the way. And I feel bad for him if he can't address those as he will never be happy, and I also realise that he has lost out hugely in losing me, whatever he says to his RL "friends" on Facebook about me. He knows he is making half of it up, and if they believe him, well, I guess I was guilty of that too, as I believed what he said about his ex having all these online affairs, and maybe she didn't. But at what stage do you disbelieve someone as a first instinct?"
I had an ex, who I knew from a young age. He had a troubled family background, his Dad was a real one for putting him down all the time, his Mum had her own issues - it gave him the perfect excuse to behave like an utter cunt and I would try to excuse him because of what I knew about his upbringing and family.
MASSIVE mistake. LOTS of people (including you!) have troubled family backgrounds - it doesn't make them all pathological liars with enormous chips on their shoulders that direct them to take-take-take and do whatever they like regardless of who it hurts. It took me a while to get past this; and to stop making excuses for him. I could construct whole scenarios around his lies to validate them; even when presented with 100% evidence that they were lies, I'd still find a way to excuse them.
I needed counselling to rebuild myself after this relationship ended - partly because I couldn't believe that I had been suckered in so badly! I still don't exactly know what drew me to him, but he was a classic EA - told me how much he'd always loved me, wanted to move in straight away, said he wanted to have babies with me within 3 months - so much shit.
Just going to repost your last point again:
"But at what stage do you disbelieve someone as a first instinct?"
Answer: every time he says anything, whether verbally or by text/email.
I know you're all loved up with Caspian, and part of you wants to share the joy with his sperm donor, but PLEASE remind yourself that he googled late abortions. That he abused you emotionally while you were sick and pregnant. That he allowed his sons to behave like little shits when all you needed was rest. This is someone who has NO "deep down goodness". There is no diamond in this particular bag of shit, he's shit all the way down.
In fact, it would be advisable for you to write down a list of all the truly bad things he did to you and print it out - keep one on your fridge, one on your mirror, one by your pillow. Remind yourself of how bad he actually was - because THAT is the true picture. That is who he IS.