Please see below for some resources that may be useful:

Trauma

https://www.rcpsych.ac.uk/mental-health/problems-disorders/coping-after-a-traumatic-event

https://www.mind.org.uk/information-support/types-of-mental-health-problems/trauma/about-trauma/

Depression

https://www.rcpsych.ac.uk/mental-health/problems-disorders/depression?searchTerms=DEPRESSION

https://www.mind.org.uk/information-support/types-of-mental-health-problems/depression/about-depression/

Anxiety

https://www.rcpsych.ac.uk/mental-health/problems-disorders/anxiety-and-generalised-anxiety-disorder-(gad)?searchTerms=ANXIETY

https://www.mind.org.uk/information-support/types-of-mental-health-problems/anxiety-and-panic-attacks/symptoms/

Self Harm

https://www.rcpsych.ac.uk/mental-health/problems-disorders/self-harm?searchTerms=SELF%20HARM

https://www.mind.org.uk/information-support/types-of-mental-health-problems/self-harm/about-self-harm/

Suicidal thoughts

https://www.mind.org.uk/information-support/types-of-mental-health-problems/suicidal-feelings/about-suicidal-feelings/

The Science of Well-Being is a free online course to develop self-awareness and improve feelings of happiness. The purpose of the course is to not only learn what psychological research says about what makes us happy but also to put those strategies into practice - https://www.coursera.org/learn/the-science-of-well-being

I am not affiliated with any of the above agencies, services or links. They are simply a directory I feel could be useful for self help, reflection and development.