You should not feel guity, or feel the need to go back. There is plenty of evidence to prove the religion incorrect in their teachings. I'm sure the people (some of them anyway) are great. If you decide to leave, you will see who your real friends are. I have a friend who was in left and went back. She was blown off from a lot of her most closest friends because the organization told them to do do so because she were no longer in the "truth"
I think that religion is all about seeing how many people they can hurt. It is not mans place to judge. I forget what bible verse that was in, but it is the truth. We should not judge one just because of what or how they believe. It is the persons own conscience to believe how they wish. They are the ones that will have to face Jesus in the end.
Best wishes.