Hey, hang in there! Do you find any comfort in talking to God? I like to read Psalms. They help me know that God is near, going through this with me. Try reading Psalm 139...
So, was your dad diabetic before his pc? or is it a result of the pc? Hope they are able to help him. Your mom, bless her, must be so close that she has to be in some denial to cope. Support her as much as you can. She has a tough job. She must know deep down that their time is short, and wants to give him every possible comfort. Your dad is truly blessed to have someone there. My dad is alone most of the time, and I want so much to be there, but can't leave my family indefinitely. He might move back closer- we'll see.
Hope you can get your diabetes under control. Do you use insulin? Try diet changes, they can make a big difference. Proteins, like almonds, can help level out blood sugars. I know what you mean, sometimes you just want it to be over! Life can be overwhelming, but hold on until tomorrow. and pray hard! take care, rt