7 to 9 hours per night of good sleep allows your body to rebalance: your body rebuilds itself, and the immune system refreshes. Your muscles recover. And you need to eat right: lots of fruits, vegetables, with a smattering of protein. You also need to stretch the muscles you have particularly stressed in your day's activity.
When you started that #2015fitnessplan, you meant ALL of 2015, didn't you? Avoid burnout by giving yourself a rest each day, too!