I'm starting to think my toe is sprained, but not sure. What should I do?

Many possibilities. Your pain could be as a result of many different things. A thorough history and physical exam and possibly some laboratory and radiology exams are needed to determine the exact cause. Causes of pain may include: trauma (fracture, sprain, arthritis), infection, metabolic conditions (gout), musculoskeletal or biomechanical abnormality and neurologic conditions (neuropathy).
See apodiatrist. If consistent pain, then you need to have it checked out.