^ yep.. it sounds like it was the drugs making you feel strung out and tense. Drink plenty of water, get some food inside you if you can, and get lots of rest - even if you can't sleep. Make yourself feel as comfortable and cosy and safe as you can. If you are scared, do you have a trusted (preferably sober) friend who could come over and stay with you? If not, and you can't sleep, try watching tv or listening to music to distract yourself a little bit.
If you feel yourself getting panicky, take some deep slow breaths and sit/lie down. Try to remember that it's the drugs making you feel anxious.
If you start to feel really unwell again or are worried that you need medical attention, please don't hesitate to call for an ambulance.. it sounds like you are okay, but it is impossible for us to know that for sure over the internet - Bluelight isn't an emergency service sadly and we are no substitute for getting checked out by a doctor!
Good luck, it sounds like you're going to be fine, especially if you can chill now and get some rest

(and no more amphetamines today!)