Sorry things are a little rough for you at the moment.
But you know what? You've got to trust how you feel.
You know your H and your situation better that anyone. And you feel there is a real chance.
Keep to that. Sometimes it'll get tough, and sometimes you'll feel negative, but you know this is just how things go.
Keep your eyes on the prize, as wise heads say.
In my experience, the only thing that worked to change how I was coping was the passage of time. I tried and tried to detach a little, but nothing worked. And then eventually, it just started to happen. Now, I'm still not great at it, and I still think about my situation and H almost all the time, but it's slowly getting better.
So have hope - that there is a real chance for a better relationship with your H, and that you will feel better regardless of what happens.