My Friend just died

I had a friend who has had a really tough life. But 33 years was all the powers that be would grant her. Yesterday at 9pm she died of Bone cancer in a hospital bed.
After years of mental illness she was diagnosed with breast cancer 3 years ago. My best friend went with her to chemo every time and we thought it great when she was told she was in remission.
Then this year we found out she had bone cancer. Always trying to make light of it, our friend said she was fine and not to worry.

Doctors told her to plan her overseas holiday this year (she had never been), but she decided to wait until next year when her pregnant sister could go with her.

I don't know how to feel, it seems so unfair that after all the crap someone goes through in life that they have to die in such a horrid way and cut short her life.

I always try to believe that there is a reason for everything, that even death is for a reason. That we grow stronger with every experience we go through. All I can think now though is that she never got to do the things she really wanted, and suffered so much.

With my life already being a soap opera, I don't know how to deal with all the extra pain at the moment. My best friend is my flatmate and is devastated but won't talk or show any emotion. I don't know what to do to help her through this.
The funeral is on Monday.

It makes me wonder how I will cope when our other friend (who I often call my angel ) finally succumbs to Huntington's disease. She has already started showing symptoms. Angel has 3 beautiful kids and has devoted her life to helping people. Is there a reason for the pain that my friends have to go through??

I just had to write down my feelings to get them out, I know that life will go on, and from when I have lost others I know that every day is a little easier to deal with. When is the level of pain a person goes through too much. Is there a limit??

If as I believe everything happens for a reason, to teach others around us lessons we need to know, what do I need to learn from this and how can I use it to help others?