What's the amphetamine? If you take more then necessary. You will probably come down with a benzodiazepine or pregabalin, gabapentin or any GABA enhancers. Huge word of caution, never use a beta-blockers like propranolol or metoprolol while on a an amphetamine at a high dose. Your health care professionals and pdocs know this, hopefully. It can cause serious cardiac problems.

You haven't mentioned the name of the stimulant and the amount you took. So, I am reading into a scrambled book!

Also, what's your "chill pill"?
If you want to talk further. The clonazepam was to try to steady you out .I assume by that token either the prescriber gave you to much stimulant and has you on a tranquilizer (benzo)- GABAa subunit bonders together.
Or you are self medicating by choosing what and how much to take?
Here we go. Stimulants cause a over fluctuation of DA and NE by back into the nucleus in very strong ways. They bind to DAT, NET, VMATs in the cells and cause the basic reuptake into the cells to reverse. That the amounts at the frontal nucleus release amps. are opened a new channel to release the pressure. Flooding the synapse, so that is why they have made slow release amps. for two reasons the FDA and pharma money. I do believe they are much less abusable and for those with ADD/ADHD past 18 pushing imho are the old school. Except the slow release but there are other less drugs without the tolerance and addicting drugs coming up after passing approval and patents. Pubmed, medscape and full studies are good. I always say the closer to our time, usually the better.There are many to check out and get lost in, but
Meta Analysis= FTW !

Good luck!