You are wondering what is going on. Where did everyone go? No, no one was abducted by aliens, no atomic bomb caused everyone to disappear. Think back to who it was that disappeared. Are the children gone? Are the ones who seemed to try to be really good people gone?
Those were the ones who had a personal relationship with Jesus Christ. They loved Him so much that they lived by His Word and tried to be the best people they could. I'm sure you remember times when they weren't necessarily good people. They tried, and though they made plenty of mistakes and were by no means perfect, they looked to the only One who was and is perfect. Jesus.
He was the one that wiped away their sins. He was the One who still loved them after they did wrong. They made the choice to push back their carnal desires and their human frailties and stand up against the world. When the world told them they were freaks, narrow-minded, and hypocritical, they did their best to put their faith in Jesus, and they waited for their reward.
It has come, and unfortunately you missed it. But, it is not too late! You can still trust Him. It will be so much harder now, but you too can have eternity in Heaven.
Go find a Bible as quickly as you can. Read Daniel and Revelation. Begin praying and pray harder and longer than you ever have. He will give you hope and will guide you. You must put your trust and faith completely in Him. Take that little step. You will receive blessings beyond your belief.