Approximately four days ago, I woke up with a red left eye.

It's bloodshot, it feels constantly strained and stressed. It has tear (clear, thin fluidic) discharge regularly. The skin is much looser, and the muscle and tissue surrounded the eye internally is extremely red and inflammed, with considerable light swelling. It is itchy sometimes; always very uncomfortable and painful. I have no known allergies, and my day-to-day environment has not changed. I have contemplated this being pinkeye, but it has not spread to my other eye, or any other person I've frequently been around. It also does not have any of the other symtoms like (thick yellow/white discharge).

Please, any information pertaining to this situation would be greatly appreciated!