Your tree is indeed declining. The cause is some type of stress such as drought (in recent years), root injury from trenching or soil compaction. Feeding the tree won't be helpful as the problem is not a lack of nutrients. At this point there is not much you can do except provide adequate watering during drought should one occur, and avoid soil compaction, trenching, etc. around the tree. Once a pine tree starts this much of a decline there is usually not a good outcome for the tree.

One other thing to check for is a circling root at or just below the soil line that is strangling the trunk. If this tree was container grown, circling roots are likely and will result in the decline of the tree years down the line. You can try to cut and remove the root but this is not very practical and may not be in time to help the tree survive.

You were so right.  My pine tree is now dead and I am having to cut it down.  I must replace this true as I have a home association that says so.  I want another pine tree.  Is there a variety of pine trees that can be planted in Spring, Tx?   I a little hesitate about planting another but I like them because they do not need a lot of limb cutting as they get taller.  Do pine trees have a large root system that my eventually damage my foundation?   How many feet from my house should I plant a pine?  One last question, what other tree can I plant that may offer some shade and the root system will not run everywhere.  Thanks.

All trees will have a root system that extends far out from the tree. Generally speaking if you can place a tree at a distance so the branches are not rubbing the eaves and the trunk is at least 15-20 feet from the home that is best.  Pines are difficult to transplant successfully from a container as they don't like the circling roots. A small pine seedling could be planted but that would likely be too small to be acceptable.
There are many alternative trees you can choose from. A few examples are Shumard oak, Nuttall Oak, Overcup Oak, Loquat-leaved oak, Canbyi oak, Montezuma cypress and Chinese elm.