Why inquest is public?

When I lost James to suicide I had to give a statement to police. It was 2020, Covid19 lockdown time... the statment was over phone. I was in shock with what had happened. English is not my first language. Looking back, Covid or not Covid the police should had come to be to take the statement and with them a mental health counselor... I wasn't given any support from the police. I was asked a statement by the phone, told that just the coroner and the police would read it... Which wasn't correct... They wanted to know how he was during his last months, and made me tell very personal things in that statement, but I wnated to help to find out what had happened, what made him do that... also, I was assure all was private, just between me, the police and the coroner... Then I find out his mother had access to my statement, and that others could request the paperwork for his inquest, because it was public... That my statement could be read in the court and that even the press could be...