How to stop fiddling around and get work done?

I have been in the industry for 3 years, I built a lot of projects but recently I started to get the itching feeling of fiddling around with low-level languages and learning stuff that I won't really need to ever use, atleast for now.

It's impacting my workflow, I currently freelance full time and I just can't focus on working on paid projects anymore.

What should I do to feed that curious baby inside me without ruining my source of income?

Maybe you can set a daily schedule, like work within specific hours during the day.

Or use a stopwatch: only run it when you are working, so at the end of the day you know you many hours you worked. Then set a target, like 8 hours per day, or whatever.

Try the pomodoro technique.

Meditation

Be on a proper work space

Don't browse the internet only open the pages you absolutely need to

Cut your actual work hours into small blocks and then give yourself some time to dick around. Example: 1 hour of laser focus followed by 15 minutes dicking around then repeat. Use a timer for this and only give yourself the 15 min reward if you do the hour of work.

Eat balanced diet and workout

Herbal teas

Classical music

No fap until the work is done

No booze until the work is done