I'm afraid of the dentist. What can I do?

Speak up, seek help. I know as a health professional that everyone is fearful of a dental procedure. It is a mini waterboarding experience. It is an issue of control and safety. Some people after several of these become a phobic patient. Start by vocalizing your fear! Ask for accommodations, including oral medications sound abatement and compassionate treatment. Place yourself in control of your safety.
Sedation. Find a dental provider that offers sedation performed by a certified nurse anesthetist or an anesthesiologist. Let the dentist be very comprehensive with your treatment plan. You can be safely sedated, have your dental work completed, and awake without remembering any of it.
Be proactive. "it ain't fun." but it can be manageable. Talk to your dentist about your concerns. He should be willing to take the time to hear you out, and then suggest things to modify your dental experience. Seek counseling to help you manage your phobias. Lean as much as you can about the tasks to be performed before you have them done so as to eliminate fear of the unknown. Sometimes meds help.
Sleep Dentistry. You may want to research dentists who use sleep dentistry. Many patients are unable to leave childhood fears behind. A kind, understanding dentist is the key. Taking some anti anxiety medication can help you for procedures which may be necessary. Start by seeing a dentist who is comfortable with sleep dentistry. Good luck in overcoming your fears! It is important to avoid big dental problems!