Hi there,
This could be any number of things, and I hope you find out what it is real soon! A couple of years ago I had a mystery eye problem. My eyes looked tired all the time like you've said. They also hurt for me and kept watering, made sleeping very difficult. It seemed to be worse if I lay down. Felt like intense watering, with a weird sensation in my head like I was yawning, only I wasn't, hard to describe! Anyway this lasted about 2 weeks and was gone within a month. During this time I went to an eye specialist who said I had under active tear ducts. It's very common, only the severe symptoms are not that common. Anyway now I have to put these drops in my eyes about twice a day, or when is needed. Don't have any problems now. But it does reoccur if I'm lazy with the drops. Oh yeh and the other symptom I had was blurred vision, like really blurred couldn't make out anything within a meter at one point. Was well numpty. So your problem may be this, if so it's easily fixed! I don't know much about the medication side of things, hopefully someone can fill you in on that. Take care, really hope you get to the bottom of this soon. I know how scary something like this is. Keep us posted, here if you want to talk. :)