If the swelling is so bad that it impairs breating and swallowing, this needs to be seen urgently by an ENT physician. If not, the swelling will go away as part of the healing process. If the swelling continues, more urgent evaluation is needed to consider to use of IV antibiotics. I would also have the throat examined to ensure there is no abscess present (in which case it may need to be drained).
The symptoms of mononucleosis will not be treated with antibiotics, and may linger for several weeks. However, it seems that the pharyngitis is the main problem here, and should be seen by a physician sooner rather than later.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
Medical Weblog:
kevinmd_b