Pretty sure this is a MLC or Identity Crisis

[tested metal]

Sorry for the length of this post. I am new so forgive me if I don't convey this perfectly.

First here is a synopsis of what has happened:

M: 34
W: 32
Married: 4 yrs. 7/20/77
Daugther: 1 yr. 7/11/10
Possible trigger: Pregnancy or earlier?
1st Bomb: 3/2/10 ILYBINILWY
Sep: 3/2/10 to 3/8/10
2nd Bomb:7/1/11
PA/EA with OM 76/15/11 to current
DSep: 8/1/11

So my W appeared to be very happy with our marriage until about 9/09 when she decided that she needed a baby. We were having some trouble, but were trying and eventually succeeded. We found out she was pregnant in Nov., then she decided to get a nose ring. Then in March she gave me the ILYBNILWY and moved out to her friends couch for a week. I used Dbing techniques of going dark and by the end of the week she was back. Unfortunately, I did not do the real work on me. I got sidelined by my job and the pregancy and although we were both unhappy I was trying to make sure we had date night once a week and fashioned my work schedule so we could spend more time together. (Our work schedules really contrasted so it was hard to see each other everyday.)

After having the baby, she really struggled with adjusting to being a mother and sought counseling. She started losing a lot of weight, which apparently her counselor told her she had an eating disorder. She then decided to change her hair from blonde to brown and got a tatoo.

In May 2011, she started saying she was sick almost everyday.
It was bad enough that we hadn't had sex for a month. Then in June we had sex once, apparently right after she started her affair. I sensed something was wrong and approached her on it and she dropped the 2nd bomb.

I asked her if she was having an affair and she denied it. My gut was telling me otherwise so regretably, I checked out her facebook and her old phone (she got a new one) and found out that she is currently having an affair.

I then (stupidly) took her ring (which she hadn't worn for a year "it doesn't fit me, I need to have it refitted")and hid it in my office for safe keeping. After 4 days she found it was missing and confronted me on it. I retruned it appologized, and explained that I wasn't thinking clearly at the time and was afraid she would pawn it and use it against me to keep the daughter. (dumb move, I know.) She then informed me that I need to find an apt. by the end of the month or she would. Being I have a lot of student loan and could not afford our apt. on my own I found a cheaper one and will be moving out on Mon.

She apparently wants to separate and agreed to a 6 month trail separation. I have been packing and not saying much to her, but have been polite at home if approached. I am avoiding texts except for the business of the separation and the ones concerning our child.

I plan to work on myself and will be more assertive in the future with everyone.

Just wanted to know what everyone thinks of this sitch. Is it a MLC? How long do you think it began. She had a gastric bypass in 2002 also so that may have triggered it. Just wondering, i am still working on myself though.

P.S. This can happen to anyone. I am a family therapist and still missed the obvious signs!