If you're now resident in Poland you would need to cancel your US membership and sign up using your Polish account.
Please send a private message with the ID for your US account so I can check this and advise further.
You can use the CC in Europe even if you have purchased in US as long as the payment is done by the US credit card from the US store.
Please refer to below mentioned link as this issue has been discussed:
Let us know if this helps,