One of the worst things you can do to yourself is cultivate grudges against your parents. They might have lacked in their behaviour towards you, they might have made mistakes, they might have been unfair to you but remember whatever they did, they did it according to what they thought was best for you.
Forgive them for what they couldn’t do and acknowledge them for what they did do and be the parent to your child that you wanted your parents to be when you were dependent on them. Reason with yourself in their favour so you can truly respect them and willingly serve them.
Allah chose them to be a way of testing you; they are the two sides of the door that has been created for you to enter Jannah. Whether you open it by pleasing your parents or let it remain shut, is ultimately your choice.