You can do this. It only feels tough because you have so much practice making other people’s opinions more important than your own. But once you turn the tide and start a new practice, things change quickly and you get to spend the next 20,000 or so days in a being exactly who you are.
Try for store credit
Sometimes a store credit or exchange will be allowed, even if a return will not. Take advantage of store credit to get something you actually want! Try to return as soon as possible, though. If you don't have a receipt , you'll end up getting back what the lowest price of the item was, and not actually what was spent!