I am sorry to hear about  the condition of your tree that you have grown for so many years.  Nor-fork Island pine is a tropical tree that does not tolerate cold temperatures below 45F. Nighttime temperatures of 50 to 55 degrees Fahrenheit and daytime temperatures of 68 to 72 degrees are best for Norfolk Island pines.  Very low temperatures (30 to 32 degrees Fahrenheit) can cause the growing tips to die and fall. Temperatures below 25 degrees Fahrenheit can cause severe freeze damage. Pruning away brown tips of Nor-folk Island pines will not encourage new growth. Once tips have died and turned brown they will no longer grow. Nor-fork Island pines require well-drained soil with high organic matter content. They need consistent soil moisture that is neither to too wet or too dry.   Water the tree from the top of the soil when it dries out.  Nor-fork Island pine trees are not actively growing in the winter so they require less frequent water and fertilization. Increase localized humidity in the winter to keep plants thriving indoors. Lack of sufficient humidity will cause the tips of their branches to turn brown and needles to drop.  An easy way to increase the humidity around your Nor-folk Island Pine by setting the pot in a shallow tray filled with water and pebbles. Plants need good light.  If the light levels are too low, the branch tips can become weakened and droop.  A good indicator to look for to see if your plant is getting enough light is that you should get from five to six branches at each node on the stem.  Trees that do not receive enough light or water will lose lower branches. http://www.ext.colostate.edu/ptlk/1321.html