Had severe sinus infection from october-april. now, sinus pressure and green discharge after lying down or when sleep deprived. fine otherwise. cause?

Chronic Sinusitis: Greetings. From what brief information I'm reading, it is surely possible that you have progressed from an acute to a sub acute and now to a chronic sinusitis. This would be a time that your nasal and sinus cavities have basically grown accustomed to having the sinuses infected. When you lay horizontal, the sinuses have an easier time draining anatomically. Also sleep loss impedes immune function.