Not sure what's wrong

My husband found this little kitten a couple weeks ago behind some dumpsters in our apt complex. He was covered in ants and fleas - I got rid of the ants and we're still working on the fleas.

He's been behaving, eating well, using the litterbox and everything until the past couple days...

He began to pee on the couch - it's a second hand couch and I don't know if the previous owners had a cat, and just today he hasn't been eating much at all.

I don't know how old he is, and I haven't been able to take him to the vet yet. I had been corresponding with some people who wanted to adopt him but I haven't heard back from them. I don't know what to do with him, I've tried cleaning the couch with vinegar, hydrogen peroxide, dawn soap and baking soda like it says on a few websites but right now it's covered in trash bags and a few old towels.

The last time he are was around 9:30 this morning.

Welcome to the Cat Site.

You do not say how old your kitten is or his weight.   Tomorrow being Monday, please try to get him to the vet.  He definately needs professional medical care.  there could be many things causing his peeing.  You can only know by getting him to the vet.

As for cleaning the couch, you need an enzyme cleaner.  Natures Miracle is available in most pet stores.  Follow the directions on the bottle.  Do not use other cleaning agents before using this.  I know you already have,  but any new ones, use only the enzyme cleaner.

Please do not adopt him out until he is healthy as any new owners may not take as good care as you appear to be doing.  Never adopt out an ill kitty.  Get him well, then find a good kind home.  Perhaps you can keep him.

Try to get him to eat something.  Kittens can dehydrate very quickly.  How about some wet kitten food, with some water added?  Right now, it is important to get him to drink.  Do not force liquid down his throat. 

Hope you can get him in to the vet tomorrow.

He has been drinking water, and licking ice cubes.

I think he's around 12 weeks old, but I'm not sure because he's on the smaller side. I think he's at most between 3-5 lbs. I really don't know though. I think I will take him to the vet tomorrow, hopefully nothing too bad is wrong with him.

Yes take him to the vet before you adopt him out!