I'm starting to think I have vaginal prolapse. How can I reverse this?

Kegel Exercises. You can decrease this sensation by doing 30-50 pelvic squeezes or "kegels" per day to increase your pelvic muscle tone.
Avoid straining. Avoid heavy lifting, straining and constipation. Make sure to have a diet high in fiber along with adequate fluid intake. A true prolapse is from weakened or torn ligaments. Prevention is the key. Once the damage occurs, the point is to prevent it from worsening.
Pelvic muscles. Although prolapse might not be reduced by increasing vaginal/pelvic muscle strength, you may be able to limit its progression. The most important time to "squeeze" is before you cough or sneeze as the force will be distributed across the muscles and not directly to your weak spots where things are prolapsing.