Until a few weeks ago, I was part of an emergency service you probably don’t know about. I’m a social worker trained as an approved mental health professional (AMHP), qualified to carry out Mental Health Act 1983 assessments. Alongside two doctors, I assessed anyone deemed to be an immediate risk to themselves or others because of their mental distress, and then devised an emergency plan to keep them safe. If treatment in the community wasn’t enough, I would section someone to a psychiatric hospital. The legislation demands that every local authority provide a 24/7 AMHP service, because of course mental health crises are not confined to weekdays.

I know what it is to tread dark paths, and the difference simple kindness and belief from others can have

I look back on some assessments and know I did the right thing. The middle-aged man who pleaded with me not to stand near his window, because he was convinced his neighbours were after him and would accidentally shoot me, clearly wasn’t coping. Or there was the time I stuffed a young woman’s detention papers into my waistband and chatted with her while she smoked before her admission (where there would be no smoking allowed), all the time praying she wouldn’t make a run for it.

I wish I had more memories like this, of detentions that felt compassionate and calm. Instead, I remember the teenage girl experiencing a psychotic episode who was found barefoot on a motorway. The local authority coolly informed me it had nowhere left to place her due to her “unmanageable” behaviour.

Then there was the woman who tried to gouge her father’s eyes out in the midst of a schizophrenic episode; he told me matter-of-factly he had hidden the knives before I arrived. Her case had recently been closed to the community mental health services because she refused to engage with them. There are always the abused and neglected, who cut and burn and starve and self-medicate themselves into hospital again and again, and who can find no solace.

Meet my patients who've been left out of the mental health conversation Read more

The majority of detentions were avoidable. I could usually identify a missed intervention, a lack of therapy, a rejection from community services that contributed to an individual’s breakdown. I started to wonder how I could look back at this job at the end of my life and feel proud, when I felt so guilty doing it.

My guilt stemmed from having experienced trauma myself. I noticed this when I spoke to patients with similar experiences to mine of emotional, physical and sexual abuse. I started seeing myself in many of the patients I detained, people whose vulnerabilities developed in their earliest years.

This “over-identification” is known to cause burnout in professionals and I was not immune. I started having nightmares about my childhood abuser, flashbacks that left me numb. I developed a bizarre phobia of illness and lost weight because I could barely eat. I kept going to work until I cried on my commute, sick at the thought of trying to be strong for my patients. I was signed off work, and felt deeply ashamed. My family, friends and partner were incredibly kind while I cried and slept for several months.

Now I have largely recovered, exuberant at being able to eat and laugh and go outside again. Sick leave gave me time to reflect on my vulnerabilities, and think about how I might continue in my role without supervision, because my local authority doesn’t provide any. I realised that I couldn’t continue without support and help.

It’s obvious in hindsight that I went into mental health services because of my own experiences. I know what it is to tread dark paths, and the difference simple kindness and belief from others can have. From talking to colleagues, I know that many have similar reasons for doing their jobs. My mistake was believing that I couldn’t be touched by others’ traumas because I was a professional.

My employers’ mistake was having no resources to recognise this as a problem. By not helping AMHPs keep themselves well, by not acknowledging that their workforce need regular time to reflect on how detaining individuals might be impacting them, my employers are perpetuating the myth that I believed in: if you are helping, you don’t need help yourself.

I’m going into minimum-wage support work now, so I can continue to be useful within my community. I’m grateful, because a few months ago I felt so broken and thought I’d never have another job. I wish that my local authority had the resources to help me before it came to this, another professional deserting the sinking ship of public services.

• In the UK, Samaritans can be contacted on 116 123 or email jo@samaritans.org. In the US, the National Suicide Prevention Lifeline is 1-800-273-8255. In Australia, the crisis support service Lifeline is 13 11 14. Other international suicide helplines can be found at www.befrienders.org.

If you would like to contribute to our Blood, sweat and tears series about experiences in healthcare, read our guidelines and get in touch by emailing sarah.johnson@theguardian.com