This is an unscientific observation from someone who has read marriage boards for 10 years. Reading these boards became my unofficial hobby after my long-ago D-Day - I took a break for several years but decided to come back and help, having that view from a distance.
Males and females tend to go through the recovery cycles differently. What you are going through is kind of normal timing for a male WS. A female WS in reconciliation tends to ask herself these questions earlier in the process; maybe at fifth to seventh month marker.
First, the female BS. Many (not all) female BS react in shock, self-blame and grief, and fear of loss on D-Day, and some try to be perfect Stepfords the first few weeks in between crying. Self-blame starts depression in outlook, that you are also experiencing now. Uncovering more deceptions (Trickle truth) usually starts the realization of a female BS into resenting that the male WS's actions have turned her into a less fun, more neglectful mother, disinterested cook, poor housekeeper, and bad friend, co-worker or daughter. Why she knows this is that people are not reluctant to tell women all of these things and call women out on it, not knowing the situation. Even knowing it, some "friends' or family will bitch at her for "failure" in these roles.
Women are judged on these things by society so harshly and so frequently that people will question and criticize her for not calling mom that week, not making dinner more than once that week or not making her famous cupcakes for kindergarten picnic and instead bringing chips. So she begins to resent the male WS fairly early in the process, even when trying to hold onto the marriage. It's a push away-pull closer problem.
Guys are less frequently judged for not buying a co-worker birthday card, for bringing chips instead of a homemade cake to a party or not calling his parents every week, and being a no-show at friends' Tupperware parties. So it takes a while before it's pointed out to him, or he noticed himself, how he's changed because of his BS status.
So males have reactions similar to female BS'es, but just in a different order of the process.
Male BS'es react first in shock, grief just as females do, and then they go into adrenaline action-based overload pushing back the inner questions while dealing with territorial protection at first. The instinct is to "win" and take control, similar to the male alpha lion that chases away other male lions. It's not a bad thing to protect and take action. It's what male mammals have done since cavemen - instinctively protect territory.
You've been so busy keep all under control - like a soldier walking a parameter to protect all, or like a firefighter battling a blaze to exhaustion, that you've have no energy left to wonder if maybe that structure should just burn itself down, to let go the protection.
I'm just telling you this is a normal phase and timing. If marriage gets better, you won't feel this changed and depressed forever. So it's time to question your wife not about affair, but how she sees life. Ask your WS directly why her life is so awful as a SAHM with money to burn and some freedom (kid school hours?).
If her affair came through depression, then maybe she feels useless and having no purpose as kids get older? Some creative or volunteer outlet to give her a new purpose might be an option?
If she's just a materialistic selfish human being, in a "Housewives of Beverly Hills/New York" kind of self-absorbed way, then that's an entirely different matter. Then you need to have a world-view discussion, and why you think that's not your value system and ask her why it's hers.
[This message edited by Heavy Sigh at 10:17 AM, June 25th (Tuesday)]