How to disable mad scientist mode in mind?

Try exercise. It quiets an overactive mind. My gym has some massage chairs and I’ll do some dev after a workout and be really zeroed in.

Test out managing your work environment differently. Some people work better in a dedicated room for work, staying away from sleep / play rooms. Make it clean. Other people are most efficient outside the house, say at a coffee shop, library, or shared workspace.

Find an accountability partner. This doesn’t need to be another dev but it might be. Someone to keep updated about what you’re working on and keep you on track. You don’t want to let them down.

If you get a part/full time job you will daydream about gamedev and be more focused on getting stuff done with the time you have to do it.