You're born with your self-worth fully intact; it was granted to you by our Creator, which you received upon conception and continue renewing and embodying with every breath you take.
Your self worth is stable, it doesn't increase when you do good things or decrease when you do bad things.
You have no say in your worth, you didn't earn it, nor did you do anything to deserve it, it's pure gift, and it's your choice to accept or reject it.
Now, your self-image, on the other hand, is a mental construct, and nothing more. It was formed by your experiences, influenced by your surroundings, and largely defined by your immediate culture.
Image is defined almost exclusively by one's outer world and physical realm, which is inherently superficial and lacking any real substance.
You may or may not have a positive self-image, and it has nothing to do with the grace gift that is your worth.
"To be yourself in a world that is constantly trying to make you something else is the greatest compliment." Ralph Waldo Emerson