Sorry to hear that. Thank you for everything that you do. I love your videos and I know many others do as well.
Maybe you can leave a comment on this person‘s website and tell them that you plan on pressing charges for copyright infringement if your videos are not removed from their website within the next 24 hours ... your videos are automatically copy written as soon as they are completed.
https://www.videomaker.com/article/c15/15953-9-copyright-laws-every-video-producer-should-know