G6
Why not just ask the Tarot about it? Just posit the question - Has someone cast a negative/ binding spell on me? Depending on the spread you use, the cards that would come up would be the Devil, 3 of Swords (Often in the use of black magic or curses), The 5 of Swords (someone actively gloating), or the 9 of Swords (psychological torture or emotional/psychic vampires)
Further edit: Almost any card could point to negativity or shadow workings, as with anything, context and intent matter a lot.
If the tarot doesn't come up with any of these or in a way that doesn't makes sense, be prepared to ask why you feel that you are being cast against. Sometimes we feel that others are conspiring against us when there're really not.
I kinda like the simplicity of just asking the question.