Help! Backless dress with Dd’s! What is the best adhesive?

Help! I just finished my 2nd alterations appointment and the alterationist put cups in my dress but that did not work. I ran out with a friend to target to get the adhesive lift. Well, for double D’s, it did nothing-it drooped down immediately. I looked into the Skimms tape from the Kardashians but it’s sold out. And I’m afraid to just purchase something random! I did see on another discussion board that Perky Pears was mentioned more than once, but when I checked Amazon, their reviews were kind of all over the place. Any suggestions would be greatly appreciated!