Have you noticed that you look relaxed and natural in the mirror but rigid in your photos? If the other photos looks natural and yours is not, it’s nothing to do with your photos. That’s how you look all the time. You are used to seeing other people in real life and when you see their photo it looks natural, and other people see you all the time like you are on the photo. Ask them if you look natural or awkward.
People looks really good to themselves in the mirror but that’s not how they look in real life. It’s the same if you record your voice and hear it back. You’ll just have to learn to get over it.