What causes small, very sore bumps on the end of my tongue?

Possibly these are irritated tongue papilla (the raised areas of the tongue) from a food sensitivity (nuts are a common cause), tooth paste intolerance or from some repeated trauma (are you wearing braces, or have other repetitive irritations happening). Some people get this just like they get canker sores else where on the tongue.

If you are a smoker, stop now!

Not a satisfactory answer, I know, but if they are not resolving within a week, then your doc or dentist should take a look.