Importance of changing bad habits:

Deciding to change the habits is not enough by itself. Rather, one needs to have motivation not only to let go of past behaviours, but also a goal in mind to go all-out toward in establishing new behaviours.

Having a precise goal in mind will help you feel that much more proficient when you begin replacing your unhelpful habits with productive ones!

Habits are created through a psychological process called the "habit loop". basically, your brain goes into autopilot in order to complete a typical behavior, and then emphasizes that process through some kind of reward or validation. This is repeated so recurrently that you don't even have to knowingly choose to complete a behavior.

Dropping a bad habit requires you to be attuned to this habit loop - in fact, hyper-awareness of a particular habit may be the thing that can help you break it.

Converging on what you're not going to do just makes it all the harder to avoid that activity - without an auxiliary activity in mind, you won't know what else to do with yourself. Think about what you can do to side-track yourself from those bad habits. Think, ultimately, about how you can replace them.