You are not alone.
There are many of us here that are in a similar situation.
Look at my stats, read my blog and you'll see I have gone through much if not all you are expressing, but so have others.
You have started down a good path here, reach out, express yourself, your frustrations etc.
This disease is horrible, particularly for us guys with advanced, however there are also a number of guys who have been living with this for 10+ years.
I'm only four years into my battle (almost four) but after I got over the anger, disappointment etc. I made what I believe to be the key to living with this disease; acceptance. I did not GET cancer, it was GIVEN to me. My goal now is to live the rest of my life, however long that is, trying to figure out why. To some, this is simplistic, to me, this is what allows me to go on day after day.
One thing I would add is this; you don't mention exercise in your posts? The medication and diet are only part of the battle, exercise is another area that can help you to help your body fight this monster.
Peace be with you.
PSA 271, bone mets, lymph node involvement
Gleason Score: 7
Taxotere + Prednisone + Atrasentan
[7th Treatment on October 13]