Is it normal that I fear of being a bad mom?

It's not that bad, if you love babies you may like it and enjoy it, you will love your child and he will become everything in your life, about your parents I'm sure they will change their mind when they see his cute little face, in the end you're their daughter and the child is their grandson and they will never change that, even his father, when he sees his child he may change his mind and help you, and I don't think he have a choice, he can't just run away, and you have a brother who support you and that's great , you can ask his help, so you can set everything right .