I'm afraid that if I become a father one day I won't be able to love my child
Why do you think you'll be unable to love your child?
I don't know who I would love more my wife or the child.
People are capable of loving their kids and their wives at the same time. It is normal to be scared of having a child.
If it's part of plan then it's okay.
It is definitely okay and I hope that you will learn to love people either romantic love for your wife and paternal love for your kids. It's possible to have as much love as you can give and as much love as you take. You will be happier doing so.