Lethargic cat with watering red eyes.

My cat is an indoor, male, Orange Tabby, about 10 years old. He is usually fairly active, following me around and always seeking attention but the last few days he has been withdrawn, lethargic (sleeping almost all day and night) and grumpy, even meowing/whining when I pet him. His eye lids are red and his eyes are constantly watering, with gunk building up around them if I do not wipe it away with a wet warm cloth. He is still eating but almost exclusively wet food as opposed to his normal dry food. Can someone please help me diagnose and treat my cat?  

Please take your senior cat to the vet. Lethargy should be considered an urgent situation, the other symptoms are also indications of serious pain and illness.

Remember that cats are the masters of hiding pain and illness, and often, through no fault of the cat's owner, by the time they show these kinds of symptoms they have actually been sick for a very long time. So do please get him medical attention right away.

Thank you for the reply, but is there anything I can do at home to help him? Like home remedies or something? I'm sorry but money is tight right now and I have been able to treat my cats at home when they were sick before. It just seems like every time I ask around no matter what is wrong with my cats people always answer "Go to the vet".....2 weeks later with some home remedies they were over to get over it without a vet. Is taking him to the vet really the only thing I can do?

Yes, a trip to the vet is best.  Once a cat starts to actually show signs of pain, they are usually pretty sick, as already mentioned.  This isn't a simple case of fleas, and very hard to diagnose without a vet actually seeing the cat and doing a checkup, bloodwork, urinalysis, etc, whatever is needed to determine the problem.  The sooner the better.  A cat's health can decline very quickly.  Now that he is showing pain, I'd say tomorrow morning if you can get an appt.