There are few topics I’m reticent to dip into because of the enormity of them. This is one such and if this tip is relevant to you, please seek further advice and assistance, it is not something you need to deal with on your own.
So, you say you’re going to leave and they reply, ‘You can’t do that, I’ll kill myself’.
Where on earth do you go from here?
Threatened self-harm or suicide is indeed a cry for help, but not one you are qualified to treat. It is often deep rooted and even if you believe you know what the underlying causes are (dubious it’s simply your unveiled plans to leave) it’s unlikely to be something you’ll be able to handle well.
If the situation seems fairly calm, you may be able to buy time and put things on ice while you find breathing space to contact their doctor to explain what’s happened. However, if things are out of hand and danger is possibly imminent, call the emergency services and request assistance from the police.
Mental health instability is very real and should be treated seriously, it is not however, a reason to keep you living with the person who is threatening it and your mental health and wellbeing need to be taken into account too. Make an appointment to see your doctor and download the situation, you may need a little of their TLC also.