advice please

[CW2017]

Hi all
my original posting it bears no real relevance to my query with you kind people today

by way of quick summary, this is my current situation and I have decided to maintain this current status quo for the sake of my 7 year old daughter. As all my "evidence" are combined cell text messages I would rather reserve those for a lawyer (not that I want to press the self destruct button on the marriage just yet). I will only confront due to unforeseen mistakes/flashpoints on their part. Obviously in an ideal world I would like it to fizzle out as we are still very strong as a couple (my choice again to maintain this). I have to get on with healing for now:
(a) D Day at New Year
(b) two amicable confrontations with an admission of half truths on her part; however she now thinks I've "moved on" from it, i.e. she hasn't got a clue what I know
(c) workplace emotional affair gets heavier (not quite full physical yet but there or thereabouts if you count groping in a disused laboratory - I kid you not!)
(d) home life unchanged (because I have been making a herculean effort as a man/husband, we are more intimate than ever and particularly in the bedroom although I appreciate there are a multitude of reasons for this)
(e) specialist councellor agrees that in this particular situation I should just play a waiting game either way (I'm damned if I do, damned if I don't) as I value the marriage so much (20 years this August) although I appreciate it will now have to be a different sort of marriage

My question to you guys today is quite a simple one: I have been through the shock, medical consequences, disbelief, depression and, more recently, acceptance (kissing and then touching someone else and what they think is the real thing after 3 months). However this week I am experiencing a new emotion: outright anger. I don't think I've seen this in many of the self-help books but I'm thinking it might be a reaction to conversations they've been having about taking it away from the workplace (they've been having clandestine country lunches, they want to socialise with work colleagues, etc.)

thank you all again