Cough with yellow mucus and fever?

I've been sick for about 6 days now. Terrible cough (which is now producing thick, yellow mucus constantly), coming and going fever, coming and going body aches, and coming and going sore throat. I also am very congested. I called my pediatrician only to find out the office doesn't accept my insurance anymore and I could not be seen or dealt with. They told me to pick up some Tussin DM and a nasal decongestant...however it's been 4 days and I'm only getting worse. I was referred to some kind of walk in clinic, but they wouldn't accept me either. I'm having a hard time with work because this is the second day I've had to call off (I'm only working there a month now). What I don't understand is that the only symptom that is constant is the coughing, mucus, and congestion. The fever (about 102 degrees), terrible sore throat, and crippling body aches come and go and usually only appear in the evening/night. Any other cold/flu I've had had symptoms that appeared constant throught the whole duration of the illness. I work fast food; I can't keep calling off with no doctors excuse, but I can't go in with any kind of symptoms. What could be wrong with me?