I've been working on my taxes all night, categorizing transactions from 2021. I went to look at a report, then clicked back on the transactions, and they all disappeared?

I can help you recover those missing bank transactions, @ldspianogirl

Can you tell me more about from what bank you are having these missing transactions? That'll help us get the best resolution for this concern. 

This can be caused by the filters you set from the Transactions page. 

Follow the steps below:

1. Go to your Transactions tab from the left menu.
2. Set the Type, Account, and Date to All. 
3. Try to check if you can now find these transactions. 

You can refer to this article for more information about categorizing and editing or recategorizing a transaction: Categorize transactions in QuickBooks Self-Employed.

Check out this article for more information about adding your transactions manually in QuickBooks Self-Employed (QBSE): Add older transactions to QBSE. It'll guide you on how to export the transactions from your bank, and import and review those transactions in your QBSE. 

Let me know if there's anything else that I can help with your bank transactions. I'm always here to assist. Take care, and have a great rest of the day!