It's not unusual during this time of year and I believe you'll come out of it being refreshed. Maybe instead of working on running or orienteering, you can just get outside and enjoy more by hiking around. The motion may help and still does good for the body. Being seventeen sounds great--congratulations!
Thanks! Yeah, that's part of what I'm thinking of doing to get back into running- first I'm going to take it slow for sure.
It's important to be excited -- or at least motivated -- to run and exercise, rather than see it as one more task of drudgery. Totally normal to need a mental break!