I am sorry that your father has been so ill for so long. It is hard to see someone you care about so ill.
Here are a few suggestions, I had a simular situation with a family member this yr myself.
He had no job,money insurance, but was very depressed.
First, try and look for county sponsered programs for the Mentally ill.
I myself called the local crisis number for him, and they were very helpful to me.
It sometimes takes a while to get an appointment thru the county, but what other opion is there right ?
I also paid out of my pocket to our DR for a few office visits. I knew that he needed to do this before his appointment for the county. He like your father was very ill.
We have had a family Dr for yrs, and knows that I have suffered with this beast myself many of times. He saw my family member, and treated him, but I paid for the office visits.
Expensive, yes, but he was very very ill and had NO money.
Walmart has five dollar RX, and Dr's have samples remember that.
I hope that this will helps. Let us know how things work out for your father.