Had meningitis from bad sinus infection. cured, but does it mean i'll always immediately get it again if i get another sinus infection?

Not necessarily: No, not necessarily. However, when you have the first signs of a sinus infection, you should see your doctor to get on the right treatments.

Unusual: Very unusual for a sinus infection to transform into meningitis. Some may recommend a careful evaluation for a defect in the bony lining of the sinus cavities that can transmit the infection, especially if this recurs. If found, the defect is repaired surgically