Despite my worst fears, you do not completely lose the ability to run if you take a week off. I was certain when I went 5 days without running that I would struggle to make it past a mile. I am not sure why...I think it is because it took me SO LONG to be able to run long distances that I am terrified to lose that now.
When I first started running, I thought that when you got tired you stopped running. So I put my poor running partner through many annoying runs when I would stop and walk every quarter mile or so. I didn't realize that you could continue to run past the point of tiredness. I don't know when I realized you could...even during my first half-marathon I kind of gave up mentally after 9 or 10 miles. I had no idea how much of running is mental.
One of my favorite things about running is the way it has changed how I think about myself. Even on the days I'm not happy with my body or I'm feeling "fat," I can still look in the mirror and think This body can run 13 miles straight. What are you complaining about? And I wouldn't give that up for anything. Thus, the fear of losing it.
Since my doctor visit I have run 5 miles, 4 miles, 4 miles, and 9 miles. I had a little pain the last 2ish miles of my 9 mile run, but overall it is definitely getting better. I don't know how runners with long-term injuries do it. I am so impressed with their mental and emotional strength to stay positive when they can't do something they love so much. It definitely motivates me to focus on injury prevention, and not take my running for granted!