How do I help my grandpa

My grandma is declining at an extremely fast rate. My grandfather feels so guilty, depressed, frustrated, etc. he is not doing well. my mom went part time at work to help take care of her to lessen the load on my grandfather. I help out once or twice a week too. Its all a lot to handle and I am really worried about my grandfather. He has been breaking down crying a lot and I don't know how to support him or what to do. I am in denial about everything. I can't get in touch with the feelings I feel like I should be having. Its making it hard to empathize and help him. I just want to make him feel better.