How To Treat Styes On Eyelids?

I have suffered w styes on my eyelids for about 3 yrs now. I now have one on the inside of my lower eyelid that looks like an ulser. sometimes i think i have allergies and i know i have sinus problems eyelids are always red burning swollen sometimes very watery they always feel very tired like i want to close them sunlight and wind make them burn and water to the point of not being able to keep them open