When I started running, it did not occur to me that running was therapeutic. In fact, it took a little while for me to see it and feel it. I think, initially, I was so focused on the run that I had not found that place of relaxation. But it came quickly. I would tell myself to relax (I still do this if I feel tense) and just run.
Like some people who crave their yoga, I crave my running (I actually do yoga too as it is great for runners or anyone). Running has now become a part of who I am. It is my lifestyle. And the fun part: I challenge myself with new workouts all the time. If done properly, the workouts are very beneficial to adding strength, and maintaining a sense of peacefulness (the therapy) that helps us get through our days.
I discovered, after losing my child to SIDS, that I needed to do anything possible to find happiness. To be happy, I needed to take care of myself. And then there was running :)
Try it. You don't have to run fast to be a runner. But you may decide that you WANT to run fast.
Have fun with it and it's a great way to meet new people. I have made some of the best friends and found the best support through my running groups. More on finding running groups later.