Having a chronic disease with no break is draining. People without diabetes or those who do not work with those with diabetes have no idea.
Each and every day you must test your blood glucose multiple times, inject your insulin/adjust your insulin pump multiple times, calculate everything that goes into your mouth, and guess what to do when your blood glucose levels are off due to stress, illness, hormones, exercise, etc. And you must do this each and every day for the rest of your life to stay healthy and out of a diabetic coma and seizure free. And stay alive.
You may be scared of having a seizure in your sleep from low blood sugars. Your fingers may be sore from poking them. You may be scared of going blind, losing your legs, or having your kidney's fail. Or maybe you are already dealing with these problems already.
You may feel mentally and phsyically tired from trying your best to keep your blood glucose values in line...and you may still fail.
There is no break. There are no nurses and doctors to do your treatments for you. There is no chance of a cure at the end of your treatment. Your treatment keeps going on and on....
This is why chronic diseases are also terrible. Sure it's not cancer, but it's like comparing bad apples to bad oranges. They both can be hard on the patient in different ways.
In the case of Type 1 diabetes, there is LOADS of research going on that likely will lead to a "cure therapy" of some sort in the near future. You need to hang on and take care of yourself as best as you can so that when that day comes, you will be healthy enough to benefit from it and return to a "normal" life. That day WILL come, and I promise you that research is closer than ever. From the looks of it, there likely will be more than one way to correct Type 1 diabetes. I can't say that a cure will be tomorrow, but trust me when I say that promising research is in *human* trials now.
Don't expect perfection, just do your best. Know that you are doing a good job. Few people have to be their pancreas all day long.
There are lots of support groups for people living with diabetes (all forms). Sometimes it helps to talk to others who know what it's like. They really 'get' what you are going through and don't just pat you on the shoulder and say "it could be worse" without knowing just how bad it can be for you.
Hang in there, there IS hope. :)
P.S. If you are seriously depressed, please talk to a medical doctor or mental health professional.