I know all too well how hard it can be to open up about mental illness and suicide ideation, especially when not all institutions can be trusted to help more than hurt. If you're struggling, or worried about someone, I've created a list of charities and hotlines on my website that could be the start of a safety net: nadireedperez.com/resources.
I’ve done my best to vet services that do not work with police in the US, but please be aware that many organizations in the UK and elsewhere are required to report to emergency services if they believe your life or someone else’s is in immediate danger. Otherwise, these charities all provide confidential services. For more specific information, you can consult the confidentiality policy of the organization in question.