Ouch! Chickadee, you sound as though you've had some nasty experiences. I hope your foot gets better quickly. Like Jivecat, I have to say I've developed a tendency to refuse or thwart a drop or seducer with men I don't trust to protect my safety (either because I've had a bad experience with them in the past or because the dancefloor is very crowded). Some men I trust implicitly even on a crowded dancefloor, but it does take time to build up that kind of trust.
I have an extremely good memory for faces so I usually know if I've met or danced with someone before - and I have an excellent memory for people I've either had a fantastic dance experience with or those who have caused me pain. The last time (about a year ago) I asked someone not to drop me at all because I wanted to protect my back, he told me he could drop me safely and put me into a drop but left his knee in the way
Needless to say I won't be dancing with him ever again. These days I would almost certainly try to resist drops with someone I've specifically asked
not to drop me.