(((((((Blueblades)))))))
If life is only 70 years long (give or take about 20 years), then there isn't much one can do except try to be content and not let the rest of your time be spoiled by bitterness and grief. Enjoy the loves of your life, as we all should.
But, if life for us is eternal, then our trials and sorrows also create the chance for eternal greatness of soul. The deep characteristics of caring, forgiveness, humility, patience, and so on, comes at a very high cost. (This thought makes me tremble a bit.) It sounds like these have been developing in your family from your post.
Personally, I believe nothing shall be wasted: not our sorrows, nor even our sins. In God's hands, it shall all be redeemed, it will all work for the good of those who love Him. It will be well for eternity. This is always my biggest comfort; I hope you can find a mustard seed of faith for that comfort, too.
bebu