You can change.
Our brain is very plastic (adaptable). And THAT is how mankind survived without speed, horns, sharp teeth, sharp claws, etc.
Our attitudes and emotions come from our subconscious. And what is in there is what WE have told ourselves.
So if you keep on saying you "don't like kids", then you are guaranteeing that you will NOT like kids. And putting your marriage at risk.
Of course you can hold someone else's baby. YOU are the only one stopping yourself from enjoying it.
Of course if you lack enough self-awareness and inner strength, you might have to talk with a therapist before you can figure out how to master your self.