Can anyone point me in the right direction in applying for a psychiatric service dog?

Can someone point me in the right direction of getting a psychiatric service dog?

Hello, I am trying really hard to find an organization that I could apply to to get a psychiatric service dog for my schizophrenia and PTSD. Does anyone know how to do it? Should I adopt a dog and train it though an agency? Should I go through an organization? I’m so lost and I don’t have anyone to help me. I don’t even know where to start. I can’t afford to spend thousands (like $50,000) and I know that this could be very expensive. Any help would be amazing. Thank you.