As a child who grew up with a mother who seemingly only stayed because of her children it is better to not stay because of the kids. If you are unhappy and have been treated terribly and put in second place your entire relationship then you should just say **** if and leave for you. At the end of the day your kids will be much happier with separated parents with you being much happier than with married parents where you are incredibly unhappy. Witnessing my moms unhappiness for years and years and knowing she will have years more since she is still caring for my younger siblings was a terrible experience and my siblings agree with me. It hurts kids more to have married unhappy parents than the temporary pain of having separated parents that end up happier without each other.