This is brain physiology, and not anything to do with your actual progress.
Your brain "sees" based on recognition of common images (anything you see often, including yourself in the mirror). It says, "Oh, I recognize what this is" based on certain basic features, then fills in the rest of the image from memory. So if you've been looking at you in the mirror for a while at a bigger size, it takes a looong time for your brain to replace the old images with the new ones. You see yourself as bigger because your brain is filling in "You" with images of you bigger.
You can break this by looking at photographs, a lot of times, since the proportions are so different that your brain doesn't fill in the images the same way. So if you haven't taken any progress pics, start! It'll be much easier to see the image change if you do. Taking measurements will help you too, to recognize that you are smaller, even if your visual image doesn't match that.
Otherwise, it just takes time...a lot of time. But eventually your brain does catch up.

on your successes so far!