The same thing happened to me a few years ago. It was horrible. One minute, he was texting me every day, then suddenly, he was gone. Realistically, there is only one of two possibilities: (1) He got tired and created a new avatar to get rid of me, or, (2) something tragic happened in RL (death, no computer, etc.) If it was the former, I wish he had just had the balls to write me a Dear Jane letter and be done with me. Since he didn't, I'm always wondering if he died. I feel your pain.
Blessings,
Igraine