The hacker logged into my account and cheated.

I'm an Apex player on Steam. One day, when I opened Steam and logged into Apex, I found out that there were other players on my account playing duo with strangers. It scared me a lot. I've never lent my account to anyone. I immediately revoked his login access, but it was too late. The stranger told me that he had cheated in the tournament and that my account had been downgraded from gold to platinum. This frustrates me very much. I felt like I couldn't accept all of this; This is an undeserved disaster for me. Please take a closer look at my attachments; I don't know the Newcastle players in the game. I don't understand why two people can be on the same account at the same time. I can even see his previous records and ratings. This guy used my account to kill 31 people and caused 6700 points of damage. When I saw it, I was simply devastated. I can't imagine my first Twin Hammer Skeletons army happening here. I've been appealing for two years now and haven't received any response. I was very disappointed.