My dog seems sick

Question
About two weeks ago, I was gone for like 15 minutes and left my dog with my parents and their 2 dogs. my other roommate the owns him as well was gone for 3 days. I came home and took my dog into my bedroom when I noticed his eye was very bulgy and it was very cock-eyed. My mom said that one of her dogs bumped his eye. So my mom called a couple places and I didn't have money to take him to the doctor but was going to take him to the vet the next day. I woke up the next morning and his eye seemed completely better, so I didn't take him. His is a 1 year old puggle. The next couple of days it seemed like he was being very careful on his eye. He would scream out if the dogs got near it and he won't open his mouth all the way to yawn. He also will not eat dog food. The only way I can get him to eat is to mix dog food with some kind of human food. He will not play with the other two dogs in the house. I took him over to my friends house and he seemed fine there, he played with her dog. But also he is sometimes very naughty when we are sleep. And digs through the garbage and he will do it if we are not sleeping too. But he won't do anything naughty now why we are awake. Only when we are sleeping or gone. Is it possible that he is just babying it? does it seem like something is really wrong? he is usually really energetic but now he just lays around.

Answer
Since pugs have a tendency to hurt their bulging eyes, it sounds like that he is having some pain after getting knocked a lot harder than anyone saw. It doesn't take much to bulge out of the socket when they are already bulging.
Since he is not playing,or eating well, he is exhibiting pain. You need to have a vet look at his eye and make sure it ok. If it was pushed out too far he can lose his sight in it.
The vet can prescribe some pain and anti-inflammatory medicines for his pain. I put my trash can on the sink when I am gone since my (10 yrs old) dog does the same thing. Under the sink works too if they can't open the cupboard. This is a bad habit that most dogs on earth have.
But that has nothing to do with his eye.
Get him into the vet's as soon as possible.