Our public community is for seeking help from the community, not for requesting account specific support. You will have to contact support to get those issues resolved. Please ensure that you read the rules and community guidelines when seeking help.
To more broadly address some of your concerns:
You have operated a seller account on our platform, which means you have an obligation to the users that you have sold content to. You can open a delete account request from your account settings page located here https://itch.io/user/settings/delete-account. Although many accounts can be immediately deleted, some accounts require a deletion request to be reviewed by our support team to verify that you are not removing content that people have paid for, and if that is the case we need to arrange refunds for the buyers in question if they are not provided with means to continue to access paid content for a reasonable amount of time.
Also, keep in mind, even with GDPR, if there is a legal basis for us to need to record information about your account then we can not remove it entirely. Processing payments, payouts, and tax information is an example of that. We are legally required to hold information about accounts that we process funds for.
Selling content online is running a business, and you need to take it seriously and take responsibility for the material you distribute, including the relationship you have with those who you have collected money from. When we work with sellers we hold them to a higher standard for this reason.
Hope that helps