There are some services you can use that will look for and take down your content on your behalf, Cam Model Protection is one. I'd also recommend creating a little watermark to go over your video, that way if it ends up being pirated then at least the people who view it can find your official stuff.
Personally, I try not to really worry about it too much. I can become neurotic about things very easily, so it's best not for me to go down that route. I figure the sort of people who would deliberately seek out pirated content aren't the same people who would otherwise spend money on me. They get off on the act of stealing it. Our pirated content can never actually replace the experience of talking to us, forming a connection, having us respond to requests or wear certain things we know they like, call them by their names etc. etc. imo most of the ones pirating weren't looking for any of that anyway, they just wanted to get off to the idea of getting one over on a sex worker. Once you put something on the internet you can't 100% control what happens to it, so I try to just focus on the people who are paying me.