The way you see yourself in a mirror is different from the way you see yourself in a lens

I thought it was just me and the funniest thing is that I look really good in the mirror at home but I don't know why

Do you have a beautifier mode activated on your phone's camera? Then they remove a lot of imperfections but they leave your skin very retouched. Equally in the mirror at home you see yourself as you are and on the phone the image is processed so you might look different in features and rejuvenated.