If you haven’t got one already its a matter of urgency that you get a girlfriend.
The trick to comfort in an arm sling is to have the adjustment just right. Also forget the hassle of feeding the arm through the sleeve of your outer clothing. It is easier and much more comfortable with the arm under the outer clothing. You can pin the loose sleeve into the pocket or turn it inside out. It seems to take a couple of weeks to totally adapt and appreciate the comfort of the sling makes up for the inconvenience. The greatest irritation when out is clerks who drop the change on the counter for you to pick up with one hand or who fail to hold the credit card slip while you sign it.
As you are able to mobilize the arm gradually increase the time out of the sling at first removing the sling wen you are at home only.
If you are in a position to practice before the sling is mandatory, a week or so should be adequate