Getting better means, for me, training myself not to act on emotions until I think through the consequences of acting.
I know that sounds simple and easy, but it's not. It's hard. It takes effort, the kind of effort you would use to learn a new profession or to excel in a new sport.
for me, it took group therapy for DBT, personal therapy at the same time, and CBT training. I'd say it was 5 years for me to see real progress. Plus, I use meds to help.
10 years later, things are noticably better, meltdown, etc, are fairly rare. Still have bad periods, but I can minimize the bad effects of those now.