Change takes courage, especially when it comes at the end of a long period of wishing, wanting, and hoping for change—but not being ready to do what it takes to make change a reality. I've made some rather monumental changes in my life, and I am willing to bet you have too.
Every change I have made started with a decision I made without fully understanding what change would look like. It's like author and motivational speaker Mel Robbins says: sometimes we are "one decision away from a completely different life." Making big changes in our life also takes time and practice, especially when the change is about stopping a behavior.
If you have made the decision to stop doing something, just keep practicing and trying. Focus on how you feel when you do succeed at stopping, and then celebrate your success.
On those days or at those times when you are not able to change something, forgive yourself and try again. You will be inclined to feel bad about yourself, to start beating yourself up.
Change that behavior too. We need courage to change because change is hard, but it's not impossible.