I gave them my bank details

Contact your bank's fraud department. Cancel your cards.

What should I do right now?

Call your bank immediately so they can suspend your account. Ask to speak to bank staff that specialise in security or fraud for assistance.
Credit card companies can reverse a fraudulent transaction if contacted soon enough.

Never respond to an email asking you for your PINs or passwords. Your real bank will never do this! They will probably be fake and lead to a scammer.
Do not try to contact your bank using any details in a suspicious email or website - they could be fake and take you directly to the scammer. Use contact details from the phone book.
Never send your personal or credit card details by email unless you completely know and trust the person or organisation.