Going to sleep when you’ve just gotten your ear pierced can be a challenge. I have a tip for that. Buy a Sensitive ear pillow like these!
You’ve seen them before. Neck pillows.
They used to be very uncomfortable but these days there are softer, more comfortable ones. For your piercing, you will not be using it as a neck pillow of course, but flat, underneath your pillowcase. It would be like a haemorrhoid donut, but for your ear. Your ear will be relieved of pressure and you will still be able to sleep comfortably on the side you’re used to.
Make sure you put it underneath your pillowcase to prevent it from getting dirty because you can’t put that pillow in the washing machine.