I get it too. I once researched it and it's "normal".
FYI:
Chronic Tonsillitis
Chronic tonsillitis is a persistent infection of the tonsils. Repeated infections may cause the formation of small pockets (crypts) in the tonsils which harbor bacteria. Frequently, small, foul smelling stones are found within these crypts. These stones (tonsilloliths) may contain high quantities of sulfa. When crushed, they give off the characteristic rotten egg smell which is well known to cause bad breath. They may also give a patient the sense of something being caught in the back of the throat.
and
White debris in the tonsils..."chronic cryptic tonsillitis". The tonsils contain many pits and pockets...called crypts. These, in some patients tend to become impacted with white foul-smelling (especially to the owner) debris that is composed of bacteria and dead cells. It may cause a low grade intermittent sore throat. Antibiotics are only transiently helpful. Some patients will use various mechanical picks and swabs to attempt removal. The only consistent cure is a tonsillectomy...althought the problem often is minor enough that no therapy is necessary.
It is possible that you have either an abscess or a chronic infection in the tonsillar tissue. The best person to see is an ENT specialist who can evaluate the situation, perhaps take a culture and let you know the next steps.