It's hard to say man. I recently went through a period where I thought I was burnt out. I was putting in a lot of mileage, then I raced a marathon where I injured my hamstring. Suffered through the race, took a week off, and felt able to run again but it was definitely a bitch, I didn't feel good and had little to no motivation that next week, literally considered just quitting. I was struggling with 8min miles when a few months ago I ran a 2:45 marathon. I ran a half marathon the next weekend and suddenly felt good again. Just comes and goes sometimes I guess. A week might help and you wouldn't lose much fitness. I'm 18 btw.