I think in this digital age it’s easier to rig up something that could help. I don’t know exactly what you DO have if you have one hand missing. But I guess it’s about figuring out what you can do with what you have.
Perhaps you can find someone who can make you a device that let’s you use what you have to control some things. All it needs is a midi interface, the right mechanics and a good mapping. Clearly you’d need to figure out which functionality you miss most because of having only one hand available, but that is something you need to figure out.
I am sure there are volunteer organisations dedicated to helping those with physical challenges who would be interested in joining you in finding a way to expand the options. Midi, mapping, programming and digital DJ software are definitely tools that will help with that.
.
