"So. I was in my first marriage for 18 years and it was over after the first year. I stuck it out even when in my heart it wasn't good. My current marriage isn't good either and I've decided not to settle. I'm just not willing to give another 18 years of my life away."
Gwyn,
AGAIN, you are making your options LEAVE OR SETTLE FOR AN M YOU DON'T WANT. The idea that these are your only two options sounds like an idea your mother has unhelpfully drilled into your head. Do you really want to be like her and count those as your only choices? You will stay as stuck as her if you do so.
What keeps happening to option 3?
Why are you so incredibly resistant to it? Option 3 is the one to pursue if you want the kind of growth you will need to be in a sustainable, vibrant, authentic, intimate R with anyone, whether it turns out to be H or not.
If a sincere, raw, risky, emotional investment doesn't lead to changes in your M that makes it one you want, by all means leave. But first try the things YOU NEED TO TRY to grow past this roadblock you have to intimacy.
