Criticism aside, that is genuinely abnormal. To frequently arrive an hour and a half late because of nothing more than psychological issues sounds like a serious problem, in my humblest of uninformed opinions. Have you thought about getting professional help, of some sort? I'm not trying to be mean, but if you're not intentionally exaggerating your difficulties, it sounds like this is a major issue in your life. What you're describing just does not seem ok. If I had that problem, I wouldn't be able to attend classes, or keep my current job. It's one thing to lose track of time and show up while the professor is giving his introduction, but you're talking about showing up to an empty classroom.