What is your "It was terrifying, but I'm so glad I did it" story?

I searched and the last thread like this is a little old, so I thought I'd ask.

Also, I've been thinking about a friend of mine lately because the year is ending. I'm about to send him an e-mail telling him how much he's meant to me this year and always. I guess this is a little of introspection as well.

When I started college I was a full blown prescription pain medication addict. My friend was my teacher. He watched me go through the ups and downs and withdraws but never said anything. A couple years later, after I got clean, I finally e-mailed him and fessed up to all of it. I thanked him for his kindness and patience. I was shaking while I wrote the e-mail and terrified as to how he'd react. Actually being honest with him grew a strong friendship between the two of us. He's been a pillar of strength in my life that I'm constantly grateful. So, the original moment was scary but paid of tenfold in the end.

Your turn. What terrified you but made a huge positive impact on your life once you did it?