It's hard to measure personal growth as it's occurring. It sneaks up on you even with a concerted effort. Until you get to your point where your actions are what you hoped to achieve.
Recently I noticed how much I'd grown in just a few months. A few months ago I was letting my lack of control of some situations and other people's actions get to me. It'd affect my mood, my day, and my choices. But gradually I forced myself to not let it affect me. Writing also helped a lot. And now in similar situations, I'm coping significantly better. I still feel disappointed or sad but it doesn't have the effect it once did.
It's also shown me the importance of accepting emotions for what they are. Instead of going around it, it's better to go through it. Accept the feeling at the moment and learn from it.
Which brings me back to how do you measure growth?
Maybe it's only possible when placed in similar circumstances. In software, you can write tests for common issues to catch potential regression. In life, it's impossible to truly simulate emotions. You can only experience them to know how you'll react. It's important to continue the tasks crucial to your growth until you see how you respond in similar situations, maybe even after you think you've grown as well.