We don't want you to feel this way, @Bridie Kiera.

Recovering the deleted transactions in QuickBooks Online is unavailable. As a workaround, you may utilize the Audit log tool to reenter the deleted transaction manually. 

Regarding the warning for deleting the transaction, there is a notification that will pop up to confirm the deletion process. I've added a screenshot for your reference:

If you're not able to see this warning notification, I'd recommend performing clearing the browser's cache. To refresh the outdated data that is automatically saved while surfing the internet.

I've added an article about getting the data from a deleted transactions: Use the audit log in QuickBooks Online.

Let us know if you have other questions or concerns in the comment section. Take care.