There is no more important goal than improving your health. Your level of health determines your quality of life. Even if you have very little in the way of material goods, if you are healthy, you have the opportunity to work, to play, to live!
In my mind, there is no greater shame than to take a healthy body, and ruin it with bad habits. Take your life back. You can do it. It's worth it. You can stall and even reverse diabetes, heart disease, limit your risk of stroke, bring your bad cholesterol down, lower your blood pressure, have more energy, increase your functionality--the list goes on! The only thing holding you back-is you.
Doubting yourself equals not accomplishing your goals.
You are not powerless to control your own demons.
Of course you can do it. Of course you can change the way you live. Of course you can make better choices. Of course you can stop eating those darn trigger foods!
I can promise you one thing: if you keep flexing that discipline muscle, you will succeed. Your doubts are what are holding you back. Deep inside somewhere, you don't believe you can do it. And the belief is what makes the whole thing fit together like lock and key. Deep inside, you believe that somehow, that donut or M&M or bag of chips is more powerful than you. But how can that be? They are inanimate, and you have the power to CHOOSE. You decide what goes in your mouth, how much you exercise, and how you live your life. You are the boss. Now prove it to yourself.