Book into an Optometrist as well - they've spent long enough studying ONLY about the eye and eyelids. Lid edema and styes and all that come from a bacterial infection or inflammation due to bacterial "exotoxins", for which antibacterial agents are pretty useful. However, which one I can't tell. If you can pop into an optom earlyish then you'll be able to start treatment soon :)
The fact that it's been ongoing for a while suggests more of an inflammation or a stye - the more milder, chronic conditions that have now become too annoying for you.
Lastly, you can't stop it now - treatment's usually about a week. However, a cold-compress might be able to help take the edge off your agony - a small towel soaked in cold water. I have doubts about using an ice pack.