Lost everything just before the halving

Today I open my Ledger live and I figure out that my bilance is 0. I hadn't much but all my funds were transferred few weeks ago and not by me. I'm very frustrated and I do not know how this could have happened. I've just try to play a bit with my ledger seed was safely stored on a secure device and I'm not able to figure out what gone wrong. Now I shall start from 0 again, I have a minimum amount on a CEX and I'll start from here again. This doesn't change my life fortunately but I learned the lesson... be careful with your private key... Just wondering what will be the best to do right now to avoid that someone claim to me that Sats possessione....