Hi, I'm John! I will help you with this.
Microsoft 365 subscriptions are tied to the country/region of your Microsoft account, so unfortunately, you cannot just change the payment currency. To pay in USD, you would need to cancel your current subscription and then purchase a new subscription under a U.S. Microsoft account.
Regarding OneDrive, your files won’t be lost if you create a new account. You will still be able to access your files using your old account, or you can move them to your new account if you want everything under one account. Just make sure to back up anything important before canceling the subscription, so nothing gets accidentally removed.
I really hope this information is helpful! Let me know if you have any further questions or concerns.
Regards,
John J.D.