Diabetes and edema...My father has diabetes and he had both of his legs amputated from bellow his knees.?

My father is 65 years old. Lately he's been complaining from swollen legs and hands, he feels bloated, constipated and his liver hurts. Can anyone help?I am really scared. He can't sleep, eat or even go to the toilet. Please don't scare me even more with some bad news. I don't know how I can help him. I live abroad, on Monday I'm flying home and take him to the hospital. Thank you. Please pray for my dad.