The "Rate Limit exceeded" error means that you hit the limit of API calls for the SQL Server connector.
There is a limit in the API calls for the SQL Server connector -- 800 calls per 10 seconds. More details about the API Calls limit for connectors in PowerApps/Flow, please check the following article:
In order to fix this issue, please consider take a try to reduce the API calls from your app to the SQL Server connector.
On your side, you should patch less records (e.g. 50 records) to your SQL table once time, and then patch the next 50 records, etc.