The idea that there isn't such a thing as right or wrong is literally as old as Adam and Eve. It may change its form from time to time - but the basic idea is always the same: It denies that God has told us that some things are always wrong and some things are always right.
Do you remember what Satan said when he tempted Adam and Eve? God had told them not to eat of a certain tree, and if they disobeyed Him and ate of it they would die. But Satan said God was a liar, and he convinced Adam and Eve that it was good to do what God had told them was wrong (see Genesis 3:1-13). Afterward - when it was too late - Eve realized she'd been deceived by Satan into thinking there was no right or wrong. Don't make the same mistake!
The most important thing I can tell you, however, is that you don't need to carry this burden any longer. God loves you, and Jesus Christ gave His life to take away your sins. The Bible says, "Everyone who believes in him receives forgiveness of sins through his name" (Acts 10:43). Think of it: You can be forgiven!
Turn to Christ and confess your sins to Him. Then ask Him to come into your life and cleanse you from all your sins - and He will. The Bible says, "As far as the east is from the west, so far has he removed our transgressions from us" (Psalm 103:12).