I believe you both have the willpower within you but you just haven't tapped into it yet. But you do have it. Find out what inspires you - what motivates you.
I lost 72 pounds and while I believed I had no willpower I was not able to lose one single pound. When I started to believe that I do have it, I started to shed off every single pound that I gained. It's all a battle in your mind and you have to take control and beat al of those lies that keep you enslaved to bad habits. It may take some time to beat it but if you keep working on your mental strength eventually you will win. It takes 21 days to change a habit in your brain. Make it your number on priority every day to strangthen you mind with motivating thoughts. I would listen to empowering music and affirmations every day while trying to lose the weight.
Also: the most crucial moments are the ones when you are most tempted. When you feel tempted.. stop everything you are doing and strengthen your mind again. Visualize yourself looking thin and hot- this really helped me.
Hope this helps you.
Blessings ♥,
Eren