Did your doctor tell you the medical term for prolonged periods? It is called "hypermenorrhea", and will help you search for information related to this condition. You can review this page for comments from other women experiencing prolonged periods, as well as treatment options at: EmpowHER Condition: hypermenorrhea.
Do you have any questions about D&C specifically? If so, you can start reading about this procedure (very common procedure!) that another women experienced at: Gina shares her D&C procedure (Video).
Lastly, you might be interested in learning more about uterine fibriods, including alternative treatments, causes and expert advice: Uterine Fibroids
Let us know if you need any additional information!