I'm here to get you pointed in the right direction to get assistance with the re-submission of a VAT return to HMRC.
In situations like this, it'd be best to reach out to HMRC to verify if you can still make changes to the VAT return and submit it again. This is to inform the agency that you're going to affix some modifications on your VAT return since the status is already accepted.
Once verified, here are some references below that can help you with handling and submitting VAT return: