The fact is: Although serving members and veterans with mental health problems can play a big part in their own recovery, they didn’t choose to become unwell. They’re not lazy and they can’t just “snap out of it”.
You wouldn’t say that someone with heart disease should just get over it; you’d expect them to see a doctor and get treatment.
The doctor would also give advice about things the person could do for themselves to help manage their condition – like cutting down on fatty foods. Mental health problems (and their treatment) are exactly the same.