Frequent eye infections with pus and blood. Why?

Hello doctor,

Since last seven to eight months I am having an eye infection, like a stye. It is getting frequent almost after every three to four weeks. I recollect having collided with somebody about one and half years back, hurt on my right eye with somebody's elbow and had a swollen eye, very painful and under the eye, it is red and swollen. After about four to five days, it started healing, and gradually I forgot about it. Now with this frequent infection in the same eye after every three to four weeks which lasts three to five days, sometimes pus and little blood come out and sometimes it heals without any pus coming out. This time it started with an itch and has gradually swollen and is very itchy and painful and red and swollen inside and outside the eye.