She looks undernourished and maybe a bit thirsty. This spring, I’d move her to the 5-1-1 (do a search) or gritty mix and begin fertilizing with Dyna Grow Foliage Plus. I’m not sure what deficiencies your leaves are showing, but doing these things should help correct them. Best of luck!

I have no explanation for the discolored leaves. Regarding fertilizer, there are lots of choices available: commonly found is Jobes Organic Citrus and Fruit Tree as well as an organic product Citrus Tone made by Epsoma. Many use Foliage Pro by Dyna Gro. I have read online that azalea fertilizer works well because citrus likes acidic soil. I haven't tried it yet. Also Miracle Gro makes a product used for acid loving plants. I have not tried that either even though I have it.

The speckled look of the leaves was caused by in insect call a spider mite. Spider mites have pricing mouth parts with which they suck the juices from the leaf, leaving the leaf with the look as show in your photo. You can read a massive amount of information concerning spider mites on the Internet. As you only have one tree, purchase a bottle of Dina gro fertilizer and fertilize the tree at a very minimum of once a month, twice a month during the warmer months. I'm surprised the tree looks as good as it does for being neglected as long as it has been. Your water source must have at least some nutrient content to it.

If so, I suggest hosing your tree off regularly and periodically spraying with neem or horticultural oil to keep them at bay. I spray a couple times a month and sometimes use a qtip with diluted rubbing alcohol to wipe down each and every leaf front and back.

Other than that, sun, regular diluted fertilizer and make sure the soil is not soggy, but don’t let it go bone dry either.

Alanna, that definitely looks like what's wrong. I looked closer and can see white specs under all the leaves and some white webbing. I'm not sure if they are alive because it doesn't look like any of them are moving. Just in case I made a remedy I found online with water, dish soap, rubbing alcohol, and vegetable oil spritzed the whole plant and rubbed it down to get everything off.

Silica, I was very suprised too, I've almost killed it a few other times and it just keeps springing back with vigor! I figured if it hasn't died this time I'll take proper care of it.

Laura, I'll go ahead and read up on it and try to move it as soon as possible. I like what I've read on the dyna grow so I'll go ahead and get it.

Denise I'll go ahead and try the dyna grow for it, I really like what I've read so far about it.

Thanks everyone for the help!!