How to make a new good habit and nuke a bad one?

Its been years since I am trying to get rid of some of my bad habits but the things are not working out. I don’t know why but somehow, procrastination crawls in and just leads me nowhere, I mean, all my thoughts , all plans, all future-schedules everything just sweeps away.
I really need to be out of this now. Please, somebody help me with an efficient way of breaking a habit and forming a new one that is rewarding.
Also, if you would like to share your personal experiences about the habits that you cut yourself free from, you are very welcome. Thanks in advance!