The main symptoms of flu typically go away after 3-5 days, but you can still be feeling bad or not 100% for, in my experiences, more than two weeks. I had swine flu when there was that major outbreak of it in North America and let me tell you, I felt like absolute death. Highest fever in my life, it hurt like heck to move or breath, my head was throbbing. Sometimes normal flus relapse, or sometimes you might catch more than one bug consecutively. Even if it was H1N1, it isn't that scary when you get it checked out and get treatment for it - but as I said from experience, it felt like the worst flu of my life. If you feel worse, it's natural to go see a doctor - hypochondria or no hypochondria. If you don't feel right at all, then get it checked and your Dr. might be able to give you some kind of prescription for whatever it is, but in the way you're describing it, it sounds like the effects of overworking your body, or, in the worst case scenario, a persistent bug that doesn't want to leave your system.