I had a mother with unacknowledged mental health issues and she didn't enjoy being with us, made it clear getting married and having children ruined her life (the only 'wisdom'she ever imparted, repeating it like a mantra throughout our teens and adulthood).
She would say she wanted to leave us regularly and then disappear for a few days then come back as if nothing happened
She was cold and brittle and not like the warm and loving mum in books/films/or like friend's mums.
But despite all this having her around was infinitely better than not having her around mainly because it is the children who feel guilty if the mother is depressed/unhappy.
I always thought it was my fault she was like that so her leaving would have been the ultimate rejection which would have been far far more damaging.
Do not leave your dc op you will cause immeasurable and lifelong hurt and damage and punishment to your children. It is not their fault you feel the way you do.
They do not need a perfect mother, they need you in their lives no matter what. Please put them first. You can get a career anytime but you only get one shot at bringing up your babies.
Concentrate on getting help and if your dh is as good as you say he is tell him you want to improve your parenting.
There is alot you can do, your posts sound like you have accepted you are a bad parent, that sounds like you are giving up on it. That can change op.
It's time to take back control and all the positive steps outlined here and all the handholding on here can help you.
Good luck op x