HR as an organization is not your friend. However, the individual you encounter in HR may be more or less favorably inclined towards you. As an example, I suffered a serious health issue and it just so happened that the HR person assigned to my case had gone through the exact same thing. That person was extremely helpful advising me of my rights and how to exercise them.

Organizations are prone to various pathological behaviors, but the individuals in them are still thinking breathing feeling human beings and sometimes they choose to act decently. Be willing to give them that chance.