You're right when you say that Jesus told us to love others -- including those who aren't particularly likeable. He said, "A new command I give you: Love one another. As I have loved you, so you must love one another" (John 13:34).
Why did Jesus command us to love others? The reason is because God loves them, in spite of their faults -- and He wants us to have the same kind of love for others that He has. Think about this for a moment. The Bible says God loves the whole world -- and yet for the most part the world isn't very lovable. In fact, the world is filled with people who don't want anything to do with God, and are living in sin and rebellion against Him. And yet God still loves them.
How do we know this? We know it because God sent His Son into the world to give His life for us and call us back to Himself. If God didn't love the world, He wouldn't have bothered to send Christ into the world. But He did -- out of His love for us. As the best-known verse in the Bible says, "For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life" (John 3:16).
Have you responded to God's love by giving your life to Christ? If not -- or if you aren't sure -- turn to Him in repentance and faith, and receive Him into your life today. Then ask God to help you begin seeing others through His eyes, and to love them even as He loves them.