O, think about your daughter. I know she is young, but she is watching you and by your example you are teaching her what to accept as treatment as a woman. How would you feel if someone treated her this way in the future? If you have trouble setting boundaries for yourself, which I understand, a lot of us do, then do it for your daughter. You are her role model. She is learning from you. Your actions speak louder than your words, and she is absorbing all of this, watching it all and recording it in her brain. And the thing is O, you are just as valuable and worthy as your precious daughter.
You should want this for your own self, but for some reason you don't value yourself to do this. You are worth more. You are worth fidelity. You are worth respect. You are worth love. You are.
I don't know how you've managed this long, the stress and heartbreak of your sitch are going to catch up with you one day in the form of illness, depression, something, I don't know what, but you can't continue this way. Put yourself first. Please, you are so worth it.