I am hanging on by a very thin thread

My grandmother is dying. I am overwhelmed with grief and guilt. Premature grief? Guilt that I haven't done more, seen her more, something... She is receiving hospice visits now. Her oxygen saturation is dropping and they will probably have her on oxygen by tonight. She's been running a fever for a few days and they say her lungs are congested. Being a respiratory therapist I find the term congested to be pretty vague, but they weren't talking to a respiratory therapist when they were reporting her condition. I'm going to see her as soon as my DH gets home. I hope I can keep from crying in her room. I hope she knows who I am. That's my selfish reason for not going more. It breaks my heart when she doesn't know who I am, who my kids are, where she is... The whole situation breaks my heart. I've been wanting to bring her home with me for years, but everyone (rightly so) says it's too much...too much time, too much work, too much emotion...too much for a woman with two children, a full-time job, and, until recently, school. I know they were right, but I also feel like I could have done it better than the nursing home, that she would have felt better, that I could have felt like I was doing everything possible. That there wouldn't have been room for the guilt.