Dear their is clear difference between your photos..
U were not able to bend knees and then after loosing Half of your weight, u were able to do thing which u were not able to do so.. what were you feeling when you finally got slim body? I mean how much u were excited about this?
That story of your moving up on stairs and your son pushing u proves it that it was really hard and tough time.
Keep one thing in mind that fat should be in proper balance in our body, sometimes people lose fats and their body do not have even the required amount of lipids/fats, which have a lot of problems like wrinkled skin and many more, so just keep balance between

Be healthy, slim and smart :)