It's one thing to ideologically be appeased to marraige, however your post says you don't feel you deserve a good marraige and a happy life.
Pyou deserve it, and your kids deserve it.
I suggest you seek counselling. Learn what is important to you, learn how to have good boundaries and what makes you feel safe and comfortable, also learn how to be a good and loving partner, but one who does not get taken advantage of.
Once you do that, maybe you will decide marraige is for you after all.