Had root canal wed, having extreme neck,ear,head pain,fever.asked for more antibiotic and got it,embarrassed to ask for more pain med,why such pain?

Hard to say...: Fever is indicative of an infection, so it's prudent you continue the antibiotics. Internal bone infections can cause A LOT of pressure, so depending on which tooth is causing you this problem, the pressure my be right on a major nerve. Your dentist or endodontist should monitor you closely... cannot tell the condition of your tooth or extent of the infection over the internet.