Pink eye is not directly caused by stress but being stressed out can trigger the outbreak of the Virus that causes pink eye.
You can try applying a cold compress to the eye or use some artificial tears to help get rid of the Pink eye.
Pink eye will normally go away on it's own though within one to two weeks but if it hasn't gone away within a couple weeks you may need to see your doctor so they can prescribe some antibiotics to treat the Pink Eye.