I am tired,weak, and conjested?

That stinks: Ok, sounds like you have a virus which are very common this time of the year. Try asking the pharmacist what the best Over the counter remedies are for you to take. If you get a fever, you get worse, your mucus turns darker, etc, then see the Dr. for an exam. Good luck, get well soon.

Many things: It is normal to be slightly weak or fatigued if you have sinus congestion or another viral illness. Be sure to get plenty of rest and drink fluids. If your symptoms persist see a doctor.

Could be infection.: How long has this been going on? If it's been a short term thing, this could be a viral or bacterial sinus infection for which treatment may be needed. If it's been more long-term, this could be some upper or lower respiratory illness. Either way, a consultation with a doctor may be in order.

Needs to be checked: You may have a viral or bacterial infection.Need more detailed history and a physical exam . And if indicated blood test etc.most likely it is a viral URI and most of these are self limiting and treated with rest , fluids and decongestants . Antibiotics only if it is due to Bacterial infection