Is professional help worth it?

Is professional help worth it? It’s a pretty straightforward question. I used to get speech therapy when I was really young, but I barely remember it. My parents said the improvement back then was night and day, and they have no idea how it worked so well. Now that I’m an adult, I’m really feeling the pressure. I still stutter, but my biggest issue is that I struggle to make phone calls. It’s affected my life and goals to the point where I need to fix it. I refuse to just live with it or accept defeat. So, my question is: as an adult, is seeing a professional actually helpful? Or is this something people usually overcome through self-therapy?