Xanax, Klonopin and other benzos always help me cool down and while they dont diminish the psychedelia much, it help me accept it, and sleep if I need to.
Antihistamines (like benedryl) can help to, with the anxiety and maybe a little bit of the psychedelia. Theyll chill you out as well, but not as well as benzos in my experience.
And lastly, Seroquel and Remeron (mirtazapine) are both notorious for basically ending a trip within 10 minutes. Remeron will end my trip within 15 minutes and depending on the dose of each I will either be able to chill, or fall asleep. I know remeron is a 5-ht2a antagonist, so it counters a lot of the psychedelia.
Besides that, just remind yourself its a drug, enjoy it while it lasts cause it doesnt last long! Its something to be cherished!