How do you know when it's time for hospice?

My husband was stricken with transverse myelitis last May and has been paralyzed from the waist down ever since -- including bodily functions. No cause for the TM has been found, which is unusual but not unknown. He has a foley catheter for urination and I manually help his bowel movements. He had a brain tumor removed this March and has lost most of his ability to speak, as well as read, write, or use the computer. However, he still has the ability to understand most of what you are saying and does have the ability to make decisions on day-to-day stuff. On his good days, he thinks like he did when he was well. But the meds he is on for leg spasms make him foggy. I think he may be developing some muscle aches and pains because of his TM and because he is not mobile, even in the wheelchair. His reactions to my moving him indicate this. PROM exercises do little to help him. He has a Stage IV sacral bedsore that is getting worse and may now be affecting his bone. To try and help this would include invasive testing and IV antibiotics, which my husband, nor I, am willing to do, especially since there is no guarantee that the bedsore will be helped. In my experience, bedsores like his, for someone in his condition, do not heal. MD said the best I can do is to keep the dressing as clean as possible. My husband is chronically anemic from all of his health problems. Hematologist does not have any remedies for this because of how all of his health issues are inter-related and are affecting each other. My husband has continually refused an antidepressant. He was a vibrant, extremely intelligent, active, funny man before the TM struck. He was a talented mechanical engineer by trade. It is beyond sad to see him in this condition. About a month ago, he started to cut back on eating and drinking. He has continued this pattern, even with my coaxing, his sister's, and that of the doctors and visiting therapists, who were coming to the home. He strongly indicates that he doesn't want to eat or drink or even take his meds sometimes. Putting your hand over your locked lips is pretty indicative of your desires. At this point, he is becoming very weak and I can't get him out of bed some days. I had him at the ER recently for dehydration and the ER MD suggested hospice. His hematologist this week suggested hospice. His primary care was reluctant to do so until some test results come back in a couple of days. Basically, there is no cure for his ills, no hope of recovery, and little hope for any improvement. When we were healthy, we discussed situations like this and we both were adamant that we would not want to persist in such a state. I try and put myself in his place and I doubt that I would want to continue with such a bleak and hopeless future ahead of me. It's been 14 mos since the TM struck and all he's done is spend weeks in hospitals, rehab, and going to medical appts. I think I'm answering my own question but I feel as if I might not be doing something that I could be doing. Or, did I do something wrong for him to get to this place so soon? I am just so alone (we are new to the area with no friends), scared, feeling inadequate and guilty. It's so hard to believe that my husband wants to leave and that we may be close to the end of our time together. I'm so very sad.