It looks like you have no better choice, mate, since the money locked up int the account is quite huge. I am afraid you are going to have to send them a photo of your passport plus other personal details if there's any chance that you will get back your money.

If you ever get back access to your account, you must withdraw all of it and transfer it to a secure noncustodial open source wallet where they will never block your account or ask for KYC verification.