Gheeeee, you think may be he figured out he is married to someone that faked attraction and used him? Do you think it might suck to realize you played like an idiot by someone you "adored"?
Frankly, you sound like a narcissist. " for their benefit, I'm sacrificing my happiness and desires and staying with their dad." Seems to me he is the sacrificing, after all you married someone that loved you and "adored you", he married someone "he grew on", and are wondering if you can find someone better basically you have no respect for him and he is to serve your purposes.
"It would be very hard to parent alone".......again its all about you.
If he is lucky you will tell the truth and do him a favor and let him find a good woman, there a re plenty out there and thats who you will be competing with in terms of "what are my chances at finding someone else desirable in my late 30s with two kids". Probably not that good, I suspect you may find you arent as attractive or desirable as you think you are. Maybe thats the problem, you think you are too good for him.