Just getting diagnosed was worth it. I tried medication and it didn't work for me, but at least now I can explain patterns in my behaviour.

Just knowing what you're dealing with is quite useful. It highlights the strengths and weaknesses you must contend with. I learned to harness my random bursts of energy, but also to control their scope.

Some things that helped: progressively removing "noise" from my life, having a maximum number of "in progress" projects, committing to smaller deliverables.