My cat has a bad case of diarrhea.?

Hi, me and my roommate just got a kitten ( about 6-7 months and weighs about 5 pounds) from our work friend about 2 weeks ago. The day we got him we noticed that he was infested with fleas, he also had a bad case of diarrhea, we also noticed that he sneezes quite a bit. That day we got rid of the fleas but all of the other symptoms still exist. Since then he's still has diarrhea, his stools are very slimmy, wet and has a foul smell it's also a very light brown color, he has trouble holding it in till he gets to one spot of the litter box. We are unable to take him to the vet because we have been busy with finals and work. A couple of days ago a friend bought him a Liquid De-wormer which we just gave to him and now his diarrhea has worsened to the point where he can barely hold it before he gets to the litter box. Please if anyone has any idea whats wrong with our kitten and help would be greatly appreciated.