Hi Redlime, and welcome
to garden.org
If you could please fill in your profile with your location it will be easier to help you diagnose your little tree's problems. Citrus diseases can be keyed to location. Also, you can download your photos directly to your post, and they will blow up bigger for us to see better.
First, a couple of questions - how and when have you been fertilizing the tree, and with what? How much water is it getting? The leaves it has look like they are a good color, but the drooping is not healthy, and the leaves are not shiny. Seems more indicative of drought than nutrient deficiency.
Is it possible that the root ball down below has dried out? When you water it, does the water rush straight through and come out the bottom really quickly? If you stick a knife deep down into the root ball, and then push a slat of wood down the cut to see how moist the soil is, that may tell you something. If the slat comes out pretty dry, you need to lay the pot on its side and slide the whole plant out to check the root ball.
