I feel like I've been fighting something for more than two weeks now (heavy head, mild headache and fatigue) but finally started having cold symptoms (runny nose, congestion) yesterday after a heavy workout. Also, two weeks ago, I spent a half a day at the spa with deep tissue massage, sauna, and hot springs. And I exercised and hiked every day for a few hours for a few days. Am I going through a detox process or did I just weaken my immune system and catch a cold?