I get migraines myself that can last for a few days or even a week if it is really bad. The migraine will tend to give one side throbbing pain, but can be both sides, pain that radiates to the back of the head and the pain will be felt in a different area than a sinus infection. Migraines tend to make you real tired because what the body goes through dealing with the pain and sometimes the residual pain of the migraine can be the worst. It is very possible that the sinus infection is throwing off your equilibrium, which would explain the they often fo that if they are bad enough. What you are describing sounds like a bad sinus infection, not a migraine. Even if you don't exhibit some of the classic signs of migraines(light sensitivity, noise sensitivity,popping lights in vision, nausea), light and noise sensitivity are usually always present, if you don't have this than I would say with confidence that it is the infection and not a migraine. And if it is true migraine pain, just being up and walking around is a challenge. The pain will make you want to detach your head from your body to get it to go away.