Fuck your New Years resolutions. Whatever you want to change about your life, start now.

When you set a goal for the start date of something, your body rewards you with a shit ton of dopamine and then when the time comes, your motivation to continue weans quickly.

Furthermore you shouldn't even be relying on motivation to achieve your goals. Motivation is fickle. You need discipline. If you wait until New Years to start something new then you're relying on motivation, if you start now you're showing that you're disciplined - and that is what will get you through the hard times.