Katherine,
There's no need to feel ashamed about your need to wear diapers as an adult. Many people have different types of incontinence and have learned to accept and deal with it successfully and comfortably.
However, a huge social stigma does exist about incontinence, which is unfortunate, but you can overcome your feelings of guilt and shame like many others have. See:
Stigma and Incontinence
http://www.healthcentral.com/incontinence/c/45/1653/stigma/
How to Deal With the Stigma of Using Diapers
http://www.healthcentral.com/incontinence/c/3328/8960/deal-stigma
Stigma in Healthcare
http://www.healthcentral.com/incontinence/c/45/12515/stigma
What's in a Name: Incontinence "Briefs" or "Diapers?"
http://www.healthcentral.com/incontinence/c/4397/25989/incontinence
Please feel free to connect with patient experts and other community members on our site. There are many people here who can relate and offer support.
Best,
Maria