I don't think HE is using the addict excuse, YOU are. Take ADDICT out of the equation. You met a guy, dated two months, he pulled a no-show on you. That's it, end of story. Why are you obsessing so much over this guy and whether he is/isn't using? So what? He showed you that he isn't into you anymore. Isn't it time to move on?
You are focussing your attention on HIS addiction/recovery. What are you doing for YOURS?