How do you cope emotionally after the amputation of a limb?

Losing a part of your body is an emotionally traumatizing experience.  With the rise in diabetes, many more adults are being subjected to amputation of limbs.  Are these surgeries necessary? What are the after effects? What rehabilitation services are available? How is one's self esteem and self image affected? How can family members and friends be supportive of one who has lost a limb?