I have one small red bump in the area at the bottom of my mouth where my gums meet my lip, right in the middle. It has a white pimple-looking head on it. It is causing me pain throughout my mouth and burns whenever I eat/drink. What could it be?

Canker sore. It's a canker sore, or an aphthous ulcer. I get them too, and they are annoying. The immune system itself causes them, sometimes in times of stress, sometimes in response to certain viruses, or sometimes "just 'cuz". Aside from a pain reliever if they are bad, there isn't much you can do, and they go away without help in about 1-2 weeks. Certain foods like citrus are irritating.
It sounds like u r. describing a pustule which could be associated with an underlying abscess.This would require proper antibiotics and possible surgical drainage.Go c ur dentist.There r other painful mouth/gum lesions possible,but the one above must be ruled out.