I recently completed a half marathon and suffered several symptoms afterwards. I have run this distance and alot further on many occassions without any ill effect. My symptoms were disorientation,dizziness,feeling of being drunk,unable to eat, blue lips and unable to speak properly,sickness. I saw the St Johns ambulance who seemed to think it was heat exhaustion, however the temperature on the day was approx 14degrees celcius although it was sunny . Is this heat exhaustion or maybe something else. I run this distance regularly, averaging about 30miles per week
Every now and then we have an "off day" although your symptoms sound quite severe, if you think you are ok, try a short training run tomorrow, if it happens again see doc.