Coffee and Caffeine FAQ

I was in amsterdam a few days ago and took some legal highs that had about 400mg of caffeine in. I didnt know this at the time and when i started crashing i had a servere headache for a few hours, no balance, irregular heartbeat and haluciniations. They are deffinatly something i will not be taking agian. I still get slight headaches every now and then (although my wisdom teeth are coming through atm), especially if i do an activity which raises my blood pressure. Have i got anything to worry about?