I'm sorry you're struggling. I get it, from my experience with my ex-MC (to whom I was very attached). I was very clear with him about how I was affected by his wife's passing and some of what he said after. In retrospect, I wish I'd backed off some, as I feel like I hurt the relationship some from being that honest at a time when he was grieving.

Note: Part of what was hard for me is that he said he wasn't going to tell us about his wife's passing (I'd found out), and I really struggled with that. So that's not the case for you here.

So while part of me says to be honest with her, I also feel maybe you should trust your instincts to not be totally open with her. The part that did help me at the time was that I was also seeing an individual T, who helped me process some of it. Is there any chance you could see someone else, even for just a couple sessions, to help you process this? I know it works a bit differently in the UK, especially if you're seeing this T through the NHS (or maybe it's a different name for mental health). Though I know there are some private T's, too. Just thinking it could help to process some things. And of course post here, if that keeps helping you.

Feel free to PM me as well.