Believe him. If he’s made himself clear that he won’t accept you and your children, then there is no partnership if it doesn’t include all of you. (I've intuitively channeled this answer for you. It's what I do. Hope it helps!)
If you love someone, you will accept all of that person, including the life that comes with them. As you’re feeling “desperate” in this situation, not wanting to leave him because you “love him”, you’re insisting that he behave in a way he doesn’t want. So what do you love, really? Do you love a person who blames you and won’t accept you as you are, as a mother? Or do you think you love the idea of having someone who you feel a connection that you enjoy? There isn’t just one person we can enjoy good feelings around. You will find someone else. Hopefully, you’ll consider not settling for someone who doesn’t accept you.
But if you do find yourself in that situation, over and over, settling for a partner who won’t accept you and your children, reflect on what you’re not giving to yourself. Whenever there is a pattern in a relationship, in this case self-sacrifice, desperation, and fear of letting go, these emotions will show up in other areas of life too. Leave this partnership for the sake of your happiness and motherhood. Reflect on the lessons that are here for you. Heal the emotions coming up that are showing up in this relationship, and are likely omnipresent in the rest of your life. You and your children deserve to be loved and accepted. But first you must learn to love and accept yourself, healing the thoughts and emotions that are unhealed so you will bring in people who won’t care if you have a family or not. They will be able to love you completely.