How was your sex life before this last miscarrage? Have you ever noticed her being moody or showing any of these signs before?
There are a couple of reasons that I don't immediately think she's involved with OM. One is that she was just too obvious about planting all that evidence.....and when you wouldn't address it,then she gives you a road map. Secondly, you're a cop and if you are very good at your job....she would know to be extra cleaver about a cover-up. She meant for you to see all that you did. The question is "why"?
I had a couple of miscarrages,too. My doctor told me that in some ways...they are harder on a woman's body than if she had carried full term, b/c miscarrying is not "normal". The body rejects the fetus. Even if just a few weeks along, the woman can feel a great deal of guilt. I don't remember feeling guilt or mourning, just a deep feeling of loss. I had done nothing to cause it....but it happened.
I knew nothing about hormones back then and I thought I could just pick up and be like always. But, having babies, or losing them, can really mess a body up. So, your W may be suffering a great deal of emotional pain,or even fear of further loss in her life. Taking in consideration of what she said about her son not needing her, her mother facing cancer, etc.
If you've checked the avenues you know to check and nothing showed up that looks like OM, then it could be that she's trying to drown herself when she goes out drinking with her GF's....if that is who's she with. They could be having a lot of negative influence on M. Was she ever bad to drink before?
So, after promising to take all responsibility for your S the next 15 yrs, where does that leave you GAL? BTW, don't make promises to your W like that. That doesn't make up for the past (in her eyes) and you shouldn't apologize for be disabled. I'm sure it did have a lot of affect on her resentment...but it's in the past.
Do not....I repeat, do not shut yourself up in your bedroom so she can have space. This girl needs strong leadership. That's not the way to do it.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!