I do not say this lightly, I believe in the sanctity of marriage, but after reading alllll of that, in your shoes, I would be seriously contemplating filing for divorce.
I agree with the other posters and just wanted to add something I picked up on in one of your responses....
It's you who failed as a wife, he's a perfect husband, so its up to you to fix your marriage????
Definitely seems like he's not interested in staying married, but he wants it to be your fault when it ends, and he wants you to fully accept the blame.
C.o.w.a.r.d
You're an exceptionally strong woman, who deserves so much better.
I read this somewhere:
"We accept the love we think we deserve."
I hope you wake up one day and realize you deserve better, and love yourself enough to pursue it too.
I don't know how you stay sane, I don't

By day you're ignored or criticized and by night you're suddenly "loved"...
That's some high school level acting right there.
You know when the bf loves you just till you give it up, then he suddenly forgets your name and number....
So that also speaks volumes regarding his level of maturity.
I would not be having sex with someone who criticized or ignored me by day but expected me to spread it at night.
Ring or no ring.
I just want to reiterate, it takes TWO people to make a marriage work, your husband has blatantly told you that he's already checked out of the marriage, by making it your responsibility.
Hugs to you