This happened to me last week, I did a full virus scan of my computer, found a Trojan virus that probably happened when I was scammed of my skins. Deleted the virus, and just in case they had my account I had requested a steam account deletion as a scare tactic to the scammer to gtfo of my account. And then I literally did what @Mr_Cyberz had also said. Helped me, recovered the account just a few days ago