Hi,
Try using Outlook web or the mobile Outlook app and see if you have the same issue limiting your sending emails.
If you have the same issue on any platform, please check for unusual activity on your account and see if there are login attempts or sending emails through a connected app or device without your knowledge. There is a possibility that you are temporarily restricted. Try to sign in again after 24-48 hours if the limit is lifted. Please try not to send any emails during this period.
If you still have the same issue, I recommend getting support for Outlook.com.
If you require further assistance, please don't hesitate to let me know.
Stay Safe!