I would suggest making an appointment with an ENT (Ear, nose & throat) specialist for an exam and accurate diagnosis.
It may be your adenoids which are lumpy clusters of spongy tissue that help protect you from getting sick. They sit high on each side of the throat behind the nose and the roof of the mouth. Although you can easily see your tonsils by standing in front of a mirror and opening your mouth wide, you can't see your adenoids this way. A doctor has to use a small mirror or a special scope to get a peek at your adenoids. You may be able to feel the swelling and soreness.
Like tonsils, adenoids help keep your body healthy by trapping harmful bacteria and viruses that you breathe in or swallow. Adenoids also contain cells that make antibodies to help your body fight infections. Adenoids do important work as infection fighters.
Because adenoids trap germs that enter your body, adenoid tissue sometimes temporarily swells (gets puffier) as it tries to fight off an infection. The swelling might go away on its own, but sometimes medical treatment is necessary. Adenoids can get so walloped by a bacterial invasion that they become infected themselves.
Swollen or enlarged adenoids are common. When this happens, the tonsils often get get swollen, too. Swollen or infected adenoids can make it tough to breathe/
It would be recommended to have an X-ray or CT scan to get a really good look at things. If it looks your adenoids are infected, the doctor may give you an antibiotic.
Here is some info, let me know if you have questions.