What an honest and brave post. And I can reassure you that you are definitely not the only one. Although it is a taboo to be frank about it.
My own story includes the fact that I have always felt the responsibility would be too big. There were more factors, but I never became a mom.
I had a South African friend once who was very honest about it too. We had long talks about how she loved her daughters very much but hated being a mum.
And nowadays, I have several young women in my surroundings who have the same kind of feeling.
I don’t think you can ever know what it’s like to be a parent before you become one. But I do think that relaxing into the fact, focusing more on the love than the negative feelings, and learning how to play again might help you get through.