First rule of business - it's business, not personal. Adcoms create these relationships with everyone they possibly can or want to. They are marketing their school, their brand, and want YOUR money and intelectual capital.
Trust me, with every top school having 100s of students, each one of them rejecting atleast an average of a couple schools, it is something they are used to. They see this 100s of times every year! And they would not have felt bad about dinging you.
If you can't make the tough decissions-easy and can't have the tough conversations in the right way, you will not make a strong business person. We all face these challenges on a daily basis. This is just part of life and the business world. You might be feeling this way, but I guarantee that the Adcoms you've been on contact with seriously couldn't care less where you go.
There are 100s of students on this website pulling their hair out, waiting for admits, hoping for their top school. Then we've got you that is like "how do I let down all these great admits?" we just had such a great relationship. Sounds like privaleged people problems. Don't let worry keep you from doing the right thing. Especially since there is someone else out there, not as fortunate as you, on the waiting list, that will get an admit b/c you decided not to go. Think about them, not about yourself.