HACKED! Someone just took control of my cursor while I was on the Internet! They started to open files and search through stuff but I immediately shut down my computer! I have been hacked and I need to know how to fix my problem???

I was watching a YouTube video when my cursor suddenly started to control itself. I had screen sharing on and remote login etc. but I have disabled all of them! I'm writing this from my IPhone because I refuse to go back online with my MacBook Pro until I know I won't be hacked again! Please inform me on my best options and where my problem might be stemming from! If it helps I will inform you that I do stream illegal Tv-Shows online and download music torrents, I'm fussing that's why all of this happened! I need to know if I can disinfect my Mac or if ill have to completely wipe it and restore it? Thanks!