Flu shot friday, yesterday very achy, no appetite, sore throat, feeling the same way today. can this be from the shot? if so how long can it last?

Unlikely: Influenza vaccine causes only two types of side effects: pain or discomfort at the injection site, usually mild and generally gone within 2-3 days; and rare allergic reactions. It rarely or never causes flu-like symptoms like yours. Probably you were just unlucky, catching a garden variety viral illness (or conceivably influenza itself) in the past few days. Contact your doctor if it continues.