What should I do about this situation?

Have your parents met her? Sometimes parents tend to say stuff like that because they haven't met their son's girlfriend yet. I suggest you try and talk it out with your parents. Why don't you ask them to give her a chance? Reason out with them. Personally, if they don't have a good excuse to tell you that she's more of a hindrance than an inspiration, I think you shouldn't let them ruin your good relationship with your girlfriend. I know, they're probably just thinking what's best for you. But sometimes parents can be very unreasonable.