Hello @Nicole Scott,
As of the moment, there isn't an integrated way to recover transactions that have been deleted along with removing your bank account. Please know that we do not wish to mess up your transaction information since it is not recommended to delete an account as discussed in the IMPORTANT box in this link: Delete bank and transaction data in QuickBooks Self-Employed.
That said, let's consider manually creating a CSV file of your bank transactions and upload them by following the steps outlined in the article: Manually import transactions into QuickBooks Self-Employed.
On top of that, I've also included this reference helpful with the steps in transactions from your receipts: Record or attach expense receipts in QuickBooks Self-Employed.
If you have any other questions, please let me know by leaving any comments below. I'll be here to lend a hand.