That's interesting that people ask when you are going to stop! The World Health Organization recommends mothers breastfeed 2 years or beyond. The AAP also recommends feeding up to 2 years and beyond. You can cite those facts the next time someone asks.

A mom recently told me she is nursing her 4 year old. She said it in a way that she was ashamed. The breastfeeding relationship is something as you said, can't just be stopped. It is a beautiful bond between mother and child and an excellent way to pass on immunities to your child. The older the child gets, the more potent the breastmilk is. It has been likened to the liquid gold that is produced in the early days just after birth for it's potent concoction of protecting elements.

Hopefully those will give you some good responses to the people who ask and also some self-confidence to know you are doing the best you can. 🙂