I am sorry to hear you are worried about your cat. My name is Rebecca. I am a veterinarian and will do my best to help.
This does not sound like a hairball problem to me. Labored breathing can be a sign of heart disease (and we do see heart problems in cats this young, particularly male cats), lung disease like infection or fluid in the lungs, asthma, or fever. If you check his gums, are they pink or pale in color? Can you take his temp with a thermometer?
Drooling can be a sign of nausea, or eating something he shouldn't eat.
If his gums seem pale, or worse, blue/purple, he needs immediate medical attention. If he has to open his mouth or pant to breathe, this could be an emergency.
If his temp is higher than 103 F, he has a fever and may need fluids and medication.
The eye discharge could indication infection or allergies that are also affecting his respiratory infection.
I am pretty worried by your description; let me know about his gums, and if you can get his temp. Do you have an emergency clinic you could go to?