Does this make sense?

[Marley]

Hi The People

Makes complete sense.
You are volunteering in a place where the users of tbe centre have mental health issues. One of these people trigger you. This person is probably aware at some level he pushes your buttons, and if he is not breaking any rules, it will be difficult to avoid him completely.
Sorry if this seems harsh, but he might not be the only one like this (get rid of him & another comes in) You may need to consider strategies to either avoid him, or work out a way for him to not trigger you. You might need to get your coworkers involved to assist with whatever decision you make.
May not be helpful
Marley