Am I a bad person? Will I be able to forgive myself? Is it normal that I made that mistake?

Look, hun, it was an internet infatuation. How do you know he was the person he said he was? Stuff like this happens all the time and nobody thinks anything of it. People expect others to lie on the internet--everybody does it, and it's why most people are so cautious online. Forgive yourself, don't lie in real life, and move on.