I don't believe that the royal family prevented her from getting help for suicidal thoughts. She must have a GP, she should have spoken to them for help; surely she could have arranged private counselling; there is always the Samaritans phone line. I'm not sure why she would go to the palace HR department for help with suicidal thoughts, I don't see it as part of their remit.
Also she made the claim that her son is being denied a title and paid-for security because he is mixed-race. If true, awful; but I do not believe that this is true.
If the royal family were so awful, why didn't they just say ok we're stepping out/back/away, the way other members of the family have done, but no they wanted a halfway system whereby they retained rights, privileges, titles, patronages, security while at the same time they intended to monetise their royal connection. If they wanted out, fine, go, be private citizens - but they wanted all the privileges but none of the responsibility, and to get privately rich off the back of being royal. The queen said no, so now they're crying about it. Truly pathetic and entitled.