Flu-like symptoms during the summer with no fever?

From Saturday night to tonight, I had this mild flu-like illness. I find it very odd as I never get sick during the summer. The last time I got sick in July was 7-8 years ago. I am a 19-year-old male living in Southern California.

I did have body aches a couple days before, but I just thought it was a reaction to severe anxiety and stress I had. The first symptom was a sore throat Saturday night. I thought nothing of it as I often have dry mouth.

Then came the other symptoms:
Congestion-mild; my nose wasn't stuffy or runny at all.
Headache
Chills-my feet especially were sensitive to the AC's cold air
Some nausea-didn't result in vomiting
Some appetite loss-I ate slower and not as much

NO Fever. Temperature remained normal the whole time.
NO Vomiting

What could I have had?

Wierd. Probably caused by a Common Cold Virus. Remember there are hundreds upon hundreds of random viruses in the Picornadae group, coronviruses, parainfluenza viruses, Adenoviruses, Rhinoviruses and other commoncold type things that cause symptoms such as yours and each virus causes slighly to somewhat different symptoms of different severities in different people.... could be anything. my guess is it will go away within a few days if not, or u get pounding severe type sinus headache with or without fever that lasts more than 4 or 5 days or becomes just imbearable, its time to go to the doctor

Otherwise fluids and a OTC painkiller/cold med is the best idea.

Sounds like a viral disease to me. You should wait a few more days. It'll probably go away on its own. If it persists, then go see a doctor.

(The fact that you haven't been sick for a few years, doesn't mean anything whatsoever.)