Similar to the way I felt about being in my marriage. Except I very much did enjoy being my husband, just not enough.
Also may be a high need for support by either person, or not being able to find enough support elsewhere, either financially, emotionally, day to day...all that stuff matters.
Marriage used to be built around building a structured, strong home that was financially sound and not so much around love. That's where the importance of family comes into play also. Small groups of people that were co-dependent.
But nowadays that's not so much how it works. And that's a good thing, because you are free to choose to leave your SO or stay with them as you choose, you don't have nearly as much social stigma to deal with. But at the same time, support is still necessary, and so that's why don't want to leave.
I don't know why people don't talk more about this. Everyone's always like, rekindle love, don't stay with them if you don't have a loving relationship...if it's not about love in a relationship, it's not worth it. But quite honestly, if you have no where else to turn, being with someone's better than being homeless.
Until you find someone else you'd rather be with at least, then you've got a right mess on your hands.
If you need to get out, there must be some sort of social assistance, government funded programs both of you can turn to for some help.
_________________
Not autistic, I think
Prone to depression
Have celiac disease
Poor motivation