Congrats on entering your eighth month!
As for your “decision” I wonder if you have taken this to counselling. I went to “marriage guidance” now “relate” when I knew I couldn’t stay in my first marriage. It was my first time in counselling and I remember the shock of being asked what my childhood was like. “The same as everyone else’s,” I said, and then told the counsellor about my Dad’s compulsive gambling and Mum’s severe depression.
You don’t have to be a couple to go for relationship counselling and the idea is to support you, whilst you work out a solution for yourself.
I decided to leave and my ex-wife and I remained friends to the extent that she and her new partner supported me through the death of my mother and came to the funeral.
Of course the outcome for you could be different, maybe finding a new way of relating, maybe deciding on no change – but at least it will offer a sounding board and some support as you work through what is a really difficult time. I hope this helps.