Hello there dear, I think we can all relate. I just get mad, too....
It's not fair that we are given this darn disease that controls so much of our daily lives. It can affect all of our decision making regarding plans with friends, work, life. As much as I realistically understand that, it's still hard to deal with.
We all manage to get by and need something that helps pull us through. For me, this disease has had it's blessings, and it helps me to realize and count those blessings. I have become closer to certain family members and friends who have been a tremendous support system for me. I feel like the disease has helped put life in perspective for me, and I feel 'wiser about the ways of the world.' I have more compassion for others and less desire to be rich and successful, more desire to be happy and healthy and live a good life. At the age of 36, I worry about different things than my friends worry about and my different perspective allows me to help them with difficult times.
There are little things you can do that make a big impact on another persons life, and can impact the world. It helps to figure out what those things are and remind yourself daily so that yes, this is not fair and you can get mad, but you also have many, many blessings in your life and things could always be worse.
Take care.