Adhesive strapless bras (HELP)

Celeste

So I recently bought a dress and top to wear for my 21st. They look awkward with a bra even if i did tuck the straps. I wear a 34D-36D. (and gravity doesn’t help the problem) I’ve been looking at adhesive bras, but I’m very cautious to buy them. To all my big boob-ed people, what helps lift and push them together? I’m just very tempted to just duct tape them if that’s my last resort.