this may not be a sty (hordeolum) at all but rather a chalazion. if this has been bothering you for a year and interfering with using your contact lenses then i suggest that you make an appointment with an ophthalmologist. these little bumps can be easily removed in their office with a minor surgical procedure.
i have a stye eyelid that has been there for at least a year could it be causing irritation with my contact lense