Have you heard the saying, "If it ain't broke, don't fix it."? There's nothing wrong with being happier single. Who know if someone will come along and change that? I wouldn't worry about it, because in the meantime, you're happy!
How come i feel more happy being single then being in a relationship?
Perhaps you enjoy your freedom from commitments. Introverts often enjoy their alone time more.
Whatever the case, that's wonderful that you don't feel the need to be in a relationship.
It's all for the Time Being.
Being in a relationship means "Sharing" part of you and being vulnerable . . . You may be still in the "Me Me Me" phase of your life, OR, you can thank your Environment and Experiences for making you the type of person that cannot be happy sharing another person's life . . .
Either way, if you are more happy single, then guess where relationship status you may want to stay?