Kim, are you aware of the affects and symptoms of growing up in the care of alcoholics? Please do some research on ACOA (Adult Children of Alcoholics). It could go a long way to helping you understand how you deal with things as an adult and also perhaps help you get a clear idea on some things that you may want to work on.
Having said the above, do understand that I have no idea what the effects may have been, for you. I can tell you that for myself, I had already understood and had been working on a lot of things in my own life, having been raised by two alcoholics, before I found out about ACOA. For me, it was a really great resource to let me know "why" and how it all tied together.
The effects certainly were not the reason my M broke down, but I did see how some ways that I behaved, prior and during the break down, were playing out.
Which definitely leads me to point to your questioning about arguments and how to deal with disagreements. You could very well be doing well in regards to that. Yet in the same token, perhaps you are reacting during disagreements and how you deal with them. Not just in your M, but in any R.
As far as going dark, it really depends on you.
Do understand, that dark... IS FOR YOU... It can help you detach. There are other possible effects of going dark, in relation to your H. Some might be positive, others negative. Just know that there will be effects.
As soon as you feel you are detached enough as an effect of being dark, will be when you decide how you will become less dark, with him.
You have had over 8 years of relationship with SD19. How was your R with her and how does it appear, now?
The argument that you had with H is unfortunate. Certainly a back slide. Just take care of yourself at this time and move forward (instead of on) from how things are, now.
The in-laws may not like the OW. Then again, only they will decide how to deal with her and your H. Understand that "moving on" is different than "moving forward", in many ways.
