I'm a horrible friend.
That's not something good, why do you think you're a horrible friend?
I don't treat my friends as I should. I'm rude and arrogant. I don't lend a hand whenever they need it.
Be honest with yourself and your friends. If you are constantly your real self and you show that to people regularly, others are going to be drawn to your honesty.
It's a big joke, I know I'm a horrible friend and I don't care.
You should still care how you treat others, specially your friend, but it is good that you have recognized your faults and it's only going to help you discover what you can do to be a better friend and see how you can have a better relationship with the people around you. Try to make an effort next time to initiate something you won't normally do so that you won't think you're a horrible friend.