I'm now 30 days without diet coke. I've been an addict for over 30 years. It wasn't easy but I feel good about it. Definitely in control and no longer a slave to a substance that I know was bad for me and totally out of alignment with my professional goals. I've decided to drink green tea instead (groan). It's an aquired taste. It's also a powerhouse of anti-oxidants and a powerful anti-inflammatory. And God knows my tired joints could use that. I've found that some of my cravings (POPCORN) have disappeared and my mouth doesn't feel so dry all of the time. And I'm not waking up 3 times a night to go to the bathroom!
Is there something you want to change? Don't try to change too much at once. Last year I tried to quit diet coke, drink my coffee black and limit alcohol all at the same time. Didn't work. Just pick one change/habit that you can commit to doing with 100% confidence for the next 30 days. It could be as simple as taking a fish oil supplement or eating breakfast every day. If you can't commit with at least 90% confidence then find another one that fits this expectation.
After 30 days pick another one. Make sure you're measuring yourself and taking stock of how you feel. Hopefully this will be motivating!