Break up your tasks into mini-pieces. Spend no more than 5 - 10 minutes on each micro-habit then move to the next. DON'T SPEND MORE TIME THAN 10 minutes. Do this for 1-2 months. Don't work toward any type of task completion; just work for 10 minutes. Actual work, moving at an easy pace, but still getting a few lines of usable code out(refactoring counts); doing a few pushups, situps, squats for your fitness. Immediately follow that 5-10 minutes of work with a reward (like playing video games, small candy, surfing the web, whatever YOU REALLY ENJOY. No judgement. It has to be something you look forward to; just timebox the reward to 25 minutes at most). Don't worry about diet; just try to go as long as you can in the morning/afternoon/evening without eating (if you can make it to 3 - 5 pm you can worry less about what you actually eat). After 1 - 2 months; add 5 minutes. Add 5 minutes every 30 days. It should be a year or more before you attempt to spend 45 minutes or more on a habit.

Don't write any of this down. Don't try to "quantify your self". Do your best to remember where you are at. If you forget, drop it down 5 - 10 minutes/ 1-3 reps/ etc. below what you think you can do currently (almost like take a few steps backward). We don't want to make a big deal about any of this. We want to be in the habit of examining how you are feeling and adjusting the process based on that; while staying in alignment with our long term goals. Real long terms goals are very hard to pin down to specifics and milestones. You are better of moving consistently toward that goal; while managing your emotional state on a day to day basis. The goal is never more important than how you are feeling right now in this moment.

Have no definitive fitness goals for 1 - 2 years (as this is about how long it takes to get the body to respond permanently to any fitness goals). Don't even think about it; just work out in short spans throughout the day. Progressively add 1 - 2 reps to each exercise every 30 days. After a year, attempt to just go to the gym for 10 minutes once a week. NO MORE THAN 10 MINUTES (even if you really want to stay). After 1 months, add another day to the gym (only 10 minutes each session). After another month, add another day (3 days total at 10 minutes only each day). From 4 months onward, add 5 minutes for every session every 30 days.

For code project, do very small projects you can complete within 30 days easily. Having a habit of completing smaller projects will pay dividends in the long run. Make the projects modular so you can easily reuse things in the future. Only build things YOU are interested. Don't worry about what language, framework, topic is popular or lucrative. Only focus on what you care about in the most selfish way possible.

To sum it all up, don't think about it anymore; just do it. And only do it for 5-10 minutes at the beginning. Follow with a reward. Progressively add more time and effort over the course of months. For the first 3 months, don't stress and move easily. Don't strive for any goal; DON'T MOVE QUICKLY. Just do it with ease. Do it as if you could forget about it in 15 minutes it was so easy. Make sure the process is getting done; and not worry about tangible results. Just make sure you are really getting stuff done in the time you are working; but moving easily, without haste or stress.