Hi there,
Welcome to Idle.
The balances section merely shows you what you have in your wallet (with the address you obscured). Idle is non-custodial. You hold your tokens in whatever wallet you have. The 465.85 USDT is still in your wallet. Additionally, if you could not approve the deposit transaction, then you could not have sent anything to the idle contract. Your funds have not moved anywhere.
Hopefully this helps,
P.S. this forum is for governance discussion as outlined in Idle Governance Forum Guidelines, not for general support, next time please use either the Discord or Telegram for general support regarding Idle.