Letting go of the one you love

I watched a very good movie - My Sister's Keeper just now. I went to watch it without knowing what the show was about...
There were quite a few heart wrenching scenes, mainly weaving around themes of lost, grieve, dilemmas, letting go...
It really portrayed the difficulties that a family with a child with cancer goes through, that pain of seeing your child die away, esp for the mum, how difficult it is to let go of her, as she finds ways and means to help her live. And the kind of tensions that it builds up within the family as the focus is on the sick child. Whereas the rest of the children play second fiddle.
I teared with them in some of the scenes, cos I could relate to that feeling of losing someone you love. And I'm so blessed because my family members are all healthy. But still grieve is real, even in terms of break up in relationships, in losing your dreams etc.
Even though the loses that I experienced seem so much milder, yet pain and grieve is real. And the irreversibility of the situation, whereby the past becomes just memories is real.
And yes in the third world, the suffering is so common as loved ones die daily because of lack of food or poor governments. Or when people die in natural disasters. The pain is so real and great.
Yet everywhere, even when we are comfortable and all, as humans, each of us suffer from different loses and grieve. As long as we are humans, and we have treasured relationships, when people die, or when people leave our lives, we grieve. As long as it hurts, there is pain. Who is to judge that my pain is less real than yours?
Its really difficult to see a loved one slowly wither away. And in one particular scene, the mum sobbed as she finally let go of her daughter. In some cases, love can be suffocating. When we love others in our own terms, and we don't want to lose the person, whereas letting go is really being loving to the person.
The greatest form of love I guess, to pray, and be happy for the loved one when he is happy. Even if he has to leave. U really wonder like, are you really loving a person by making him/her stay with you, or is it really for your own sake that you want he/her to stay (i.e. to live on?).
Letting go...is such a painful thing to do...