StellarRT There are currently some issues with sending XLM in Stargazer.
I would recommend you to install a new wallet, like https://solarwallet.io/ and when you are creating an account select the option "Import Existing". There you enter your secret key, starting with an S. Make sure to never share this key with anyone.
To access this secret key you should open Stargazer and click on this button in the upper right corner. Then select "Advanced" -> "Export Account". Now you should be able to see the long key starting with an S. If you double click on it you will copy it.
If there is no secret key shown, you will need to first remove the password from your Stargazer account.