Specific resources for psychedelic-related problems

Psychedelic Support
List of mental health providers or support groups in your area.
https://psychedelic.support/

Fireside Project
Call or text the Psychedelic Support Line for emotional support during and after psychedelic experiences.
Call or text: 62-FIRESIDE
https://firesideproject.org/

Shine collective for psychedelic survivors
Support group for those who have experienced sexual violence or other forms of harm in a psychedelic setting.
https://shinesupport.org/

ICEERS support service
Offering five free counsel sessions for people who have had negative psychedelic experiences.
https://www.iceers.org/support-center-2/

Perception Restoration Foundation
List featuring Specialist from different countries with expertise in HPPD.
https://www.perception.foundation/specialists-directory

Support Services

If you need immediate personal assistance, you can always visit the emergency psychiatric services at a hospital near you.

If you are in a life-threatening situation, call emergency services, and in dangerous situation, call the police. You can find a list of worldwide emergency numbers here:
List of emergency telephone numbers - Wikipedia

Additional resources: 

United Kingdom: List of Crisis Hotlines provided by Mind.org
https://www.mind.org.uk/information-support/guides-to-support-and-services/crisis-services/helplines-listening-services/

United States of America: List of Crisis Hotlines provided by the APA
Crisis hotlines and resources (apa.org).  

Helplines, suicide hotlines, and crisis-lines from around the world
https://www.therapyroute.com/article/helplines-suicide-hotlines-and-crisis-lines-from-around-the-world

International mental crisis hotlines
www.telefonseelsorge.de/international