Mental breakdown is not a medical condition.
usually people use the term to avoid using taboo words like depression, panic attacks, psychosis etc - but thankfully I’m hearing far less use of the term then say 30 years ago. It’s good people are much more able to state exactly what their mental health issues are . I think it’s also changed with introduction of SSRI antidepressants in late 1980s and antipsychotics in 1990s and earlier, beta blockers. GPs need to give more precise diagnosis now and patients are more informed of their conditions and have a language to use with others.
How it feels will depends entirely on what mental illness you have and its symptoms . A doctor needs help you with this.
you could search in line for common illnesses and their symptoms including : stress, anxiety, depression, psychotic illnesses such as manic depression or schizophrenia and particularly relating to hallucinations and/or “unusual beliefs”,. This may help clarify the symptoms you feel.
whilst you’re eating for GP appointment, write a diary with a scale of how bad your symptoms are , at set times during the day, say 3 or 4 time# per day, the GP will find that very helpful to diagnose what’s going on.
however, if you are thinking of harming yourself, (including scratching, bitting yourself, all the ways to using a blade) or have intrusive thoughts of suicide then calll 111 now. If you are actively planning on how to take your life or have tried, call 999 now or go straight to A&E
you can also talk to Samaritans phone line 24 hours a day if you need to talk whilst you wait for a GP appointment .
when you call the doctors for your appointment , be clear with receptionist - you can say you feel like you may be having a “ mental breakdown” or that you are having intrusive thoughts, if that is happening. That’ll trigger a safeguarding urgency and hopefully get a doctors appointment urgently.