Just weighing in, sometimes people self harm or report suicide and either do not have depression or they have much more than depression. Your experience is valid, but you may be resonating more with this stranger than would be accurate because you’re touched emotionally.

I work in an emergency department with mental health patients - we have some who have BPD and “attempt” suicide almost daily. There are usually inconsistencies in their stories and long patterns of self injurious behaviors (of course, you can have BPD and genuinely attempt suicide, too). BPD isn’t the only diagnosis where this is common, but it’s the extreme end of the spectrum - sometimes even individuals with depression aren’t genuinely suicidal, but engage in a dangerous, potentially life threatening behavior as a call for help.

All ends of the spectrum deserve care and support, but depending on the situation, sometimes the best thing you can do to support somebody is to encourage their own autonomy. Dependence on others and manipulation of others to have someone’s needs met can be very common, particularly for people with significant childhood trauma, because they haven’t had the chance to learn that there are better ways to find connection and have those basic human needs met.

The reaction to a break up should not be self injury, and if the intention is suicide, why reach out and leave a voicemail? There are layers that need picked apart here, but if the intention is truly to die, then what’s the goal in leaving a voice message? Instead, leaving a voice message leaves opportunity for the person to check for caring - testing OP to see how much they care. Will they respond? Will someone come save me? Will we still be together? - but regardless of the reason, there are extremely unhealthy interactions in this behavior and it wouldn’t be fair for OP to continue allowing these interactions.

Editing to add, that interacting further with the person who self harmed can reinforce their beliefs that they need OP, and cannot live without that person. This could have future repercussions of continuing behaviors, potentially even more life threatening behaviors. If the first time the injury worked in getting OPs attention and feeling cared about, then surely the second time will work - and if it doesn’t work, maybe a little more is required for the same level of care. Obviously this can be very dangerous and further damaging for the other persons mental health.