Have you had the experience of not doing what you said you are gonna do!
Made a plan but not taking any actions!
Said something but not having your own words!
It sounds kind of frustrating. Perhaps you feel like you are acting like a child. Some people have a feeling of not being reliable or being ashamed.
 Because of those kind of behaviors and the terrible feelings afterward, Usually people start doing procrastination. By doing procrastinate another cycle will start which is the cycle of beating up yourself.
Unfortunately, this cycle getting worse by going further and taking you to another horrible cascade which tries to make you distracted by overthinking, overshopping or overspending time by doing meaningless activites...
So as you see the wrong cascade starts with:
1. Shallow decision (no integrity)
2. Not taking actions
3. Horrible feelings (Fear, Shame, Regret, Anger,Childish behavior)
4. Resistance (Procrastination, Beating up)
5. Distraction (overeating, overshopping, overspending time)
What would be the solution:
Simple solution: Just working on your first step which is making a strong decision.
When I say simple, it means that it is really simple but it does not mean it is easy. It means you need to practice it until it gets to the skill level, then at that time it will be easy. Exactly like when you are practicing playing some instruments, It is simple but you need to practice it over and over to get the skill of playing. The actual joy comes out of it when you are able to play the beautiful piece of song skillfully.
Let's do this simple practice for increasing your skill in making the strong decision:
Choose something that you are planning to do tomorrow. Try to do that in a measurable pattern. It means that When and for how long you are gonna do that task. For example, If I plan to write an article for my website. I need to determine that I need 1hour to find a good topic and write it down and spend another 1h for uploading and editing it.
Then when you did your task, take a look back to see if you did it exactly like what you said. If not, be curious about how you can make it more realistic next time to make that happen exactly based on your plan. The more you practice this integrity technique, the more you will be expert in it. 
The point is, when you are predictable for yourself then the world would be able to rely on you.
If you are curious about other tools for making strong decisions, just feel free to sit in a one-on-one session with me. By working together, I would be able to guide you to clear up your mind and break your current pattern in order to build up an amazing new pattern for you.