Hey gusys,
Thanks to all of you, as written before, the priv key was beloging to a Stellar wallet (I forgot to have a XLM wallet). he funds have been already moved to another wallet for safety reasons afer importing the private key on a oniine wallet.

I was pretty lucky trying with that specific wallet and to be able to recover my funds even without remembering at what coin my wallet was beloging!

People out of here, stay away from any person asking to you your private keys, as the other said to me. Fortunely no one tried to contact me so far