You have 18 years of parenting ahead of you. You must learn to prioritize when something is wrong with your child.
Crying happens. Not eating? Call the physician immediately! He's an infant, he needs fluids and nutrients immediately for brain development and everything else.
You must absolutely not get in the habit of going on line, whether to anonymous internet forums like Mamapedia or to research symptoms. You have to call the medical professional who knows your child best. You don't fool around with an infant. Your doctor's phone number works 24 hours a day. After hours, you'll get an answering service trained to ask questions of parents and refer those to your doctor or the partner pediatrician on call (usually someone in the same practice).
If you do not have a doctor whose staff welcomes calls from parents, especially new parents who are still learning, you need a new doctor immediately.
Get off the internet, call the pediatrician, and report what's going on. In the future, take notes to help your memory - when it started, when you tried to feed him, whether he ate at all, what his other behaviors are, if he has a fever, whether he has changes in his throat, nose or ears, and so on.
I think you need to get through this issue, and then you need to ask your doctor to refer you to some local parenting classes and a support group so you can learn more and have more confidence. We are all doing this business of raising kids without an "operator's manual." So we have to use experts and get some education.