I feel like leaving my friend when she needed me.
Isn't she your friend so why do you want to leave her?
It is better for her to be alone rather than have a bad friend
You might not be a good person but it is never good to abandon a friend. It will hurt them and make them hard to trust others in the future.
I did it because I need to go out to have fun. I don't have time for her.
Oh, I see where you are coming from. I guess sometimes it's important to have time to yourself, but you should still be available sometimes so you don't end up abandoning her. I do believe it's not necessary to always be there for the person, but definitely don't abandon her for good, because you never know when you need help too.