Just got hacked and the hacker played 3 ranked games and won 2 XD

I got hacked and this is 5 minutes after im writing this. The hacker was still playing in my account when i tried to long in. I was so confused so I kept trying to log in and as soon as the game ended I realized that my account was hacked and the hacker was playing ranked lol. However he played 3 ranked games and he won 2 of them XD (Guess it was not bad getting hacked).

Update: I did change my password, seems like the hacker couldn't hack my email to change password

Update 2: Be careful of these hacking cuz i just got perma banned bcaz that hacker probably used some 2rd party software in my acc