My Father did something similar. He was very ill for a year before his death. He had a large suspect growth on one of his kidneys, and the doctors said he wouldn’t survive surgery to remove it. At least that’s what was said when we were present. I have a feeling that he decided not to go through treatment, and asked the doctor not to tell us anything more than what we already knew. the reason why I say this is because he told me once that he only had a year to live, but didn’t go into any detail.
I think the reason why he did this is because he didn’t want to spend money on treatments. He would rather have left it behind for us. Money wasn’t an obstacle for him, but I can see him thinking it would be better for us to have it than to waste it on medical and die anyway. I sent him once to my husbands pain management doctor to try and get some relief. The doctor injected his spine under xray, and told me afterward he suspected renal cancer.
So, I think your Father may be doing the same thing. I think he wanted to go through his treatments privately and spare the family of all the gruesome details. He may have initially told you of his diagnosis, but decided to keep the rest of the details to himself both to spare you and so that you wouldn’t treat him “different”.
For now, allow him the dignity of his privacy and focus on spending time with him as much as you can. It would be a very good idea to contact a local chapter of hospice for guidance in this matter. Hospice can help you understand what is going on with him, and give you tips on how to deal with this on a personal level. Hospice is a great help to the families of terminal ill patients.
They can help you find peace in all of this. My heart goes out to you.