How do you know if you suffer from primary insomnia?

You should see a sleep specialist to give a thorough history, so they can determine if you in fact, have insomnia or possibly another sleep disorder. This can be determined through a personal sleep log or possibly a diagnostic test.

Primary insomnia is a sleep disorder characterized by persistent difficulty initiating or maintaining sleep or by persistent nonrestorative sleep that cannot be attributed to another sleep disorder, medical condition, psychiatric condition or an environmental cause (such as drug abuse or medications effect).