This worked for me, but the necessary step was understanding why I'm doing the things I'm doing. Long term habits are serving some need, changing them overnight to habits that are better for you but don't serve that need - isn't very likely to work.

For example I had problems with playing video games, and quitting single-player games was easy once I started walking/biking listening to audiobooks or podcasts. It's similarly relaxing. There's even CRPG-like progression angle - I measure how much I did through the year and see my average speed go up.

But I still craved multiplayer games, because they serve a different need. You don't play dota to relax, quite the opposite :) In this case a 3min chess game now and then and playing D&D once a week scratches that itch and is much harder to abuse.