Advice about a sick kitty, please!?

My male kitty, about a year old,inside only, seems lethargic and is only eating and drinking a little bit. He is so tired that he just laid in his litter box for a couple of minutes after he peed. He hasn't been neutered yet, and his testicles seem swollen. I am taking him to the vet in the morning, but I am hoping someone can give me some idea of what is wrong and what I can do until we can get to the vet. This is the first kitty I have ever had, and I am still learning about cat care. Any help is appreciated!Advice about a sick kitty, please!?
It sounds like he might have a urinary tract infection, which is somewhat common but they vary in severity, He might have also got into a toxin which made him ill.Advice about a sick kitty, please!?
I have had many many cats over the years. You need to get him to the vet NOW. I can usually give advise on taking care of them at home but this situation sounds like he may not make it until the morning. Don't call for an appt. take him in and get treatment now. Good luck and I hope that he can be helped.
I agree with Suki. Maybe he had to try extremely hard to even go to the bathroom, and that's why he just layed down because he was so tired. He needs to be able to go to the bathroom, otherwise everything will get backed up and something worse could occur like a urinary track infection.
Seeing he is a kitten, I am ruling out some of the things I read about tumors. It sounds like a urinary tract infection. If he gets worse or if you can see blood in the urine, call the vet to see if there is an emergency vet available.
Please take him to the vet ASAP. This sounds like a testicular torsion, where the testicle pretty much 'spins' on itself, cutting off the blood supply.