How does change happen and how do you keep that change?

I have been a person with severe anxiety in my last 10 years. Because of my worries and the negative vibes caused by those worries, I've broke my family's heart.

When you worry too much about your family to protect them from harm, I've realised I was the one who was harming.

After being cut off by them for a while, we finally re-united, but I know that another case of such a psychological torment on my family will destroy it.

I want to change. I have to. But I don't even know the right question.

I want to be a happy, worry-free person as well as someone who gives happiness and hope to others.

But I even worry about the change?

How do I start?