Hey mate, stay calm, stressing is just going to further your hair loss.
You might be paranoid, about your hair loss, it's normal for you to lose 50-100 hairs a day as 10% of your hair goes through the telogen phase. Quote me if im wrong, but i think Nizoral does have DHT blockers, which may have really screwed up your hormone balance. (It;s unlikely, but definitely a possibility if you were over-doing the application. It might be worth you getting a blood check at your local GP, to check your hormones are all imbalanced or not. If that helps you sleep at night. Stay strong buddy pm me if you need to vent!