There's not much you can do if you don't want to go to the ER (don't understand this, it's your health...). Make sure you drink enough. 0.5l of water or sports drinks (no energy drinks!) every 1.5h or so in sips, not gulped down, should be more than enough. Make sure you don't drink too much. Keep an eye on your body temp and your heart rate. Call someone to make sure someone is with you who is able to call an ambulance when needed. And try to relax, put on some relaxing music. And above all, stop taking more. First thing you should do if against advice you don't want to go to the ER, is call a friend to stay with you I think. You really need someone to watch you, because you are probably not in a state to make a judgement call anymore I think