I got engaged to the wrong person. How do I face everyone?

I posted another question. WIthout getting into too much detail, I realized I agreed to marry the wrong person. He was my boyfriend for 7 years but he is not right for me. I need to call off my wedding next summer, but how do I tell people???

How do I tell my parents?? Friends??? Everyone else that asks me???

I'm so embarrassed. I made a big mistake in getting engaged.

PS - It's not like I'm 15 - I'm 24 but I got engaged to the wrong man, hoping he would change and fall in love with me. I realized now he wont.