maybe a picture would be nice? i suspect not enough fertilizer, or too much water.

I can't post a picture right now. The leaves just look like they are green and yellow marble. I'm pretty careful about not over watering, I tend to err on the other side of that problem. The fertilizer I used was the powder kind that you sprinkle on the dirt and then water really well, is that OK? I couldn't find any liquid citrus fertilizer at the garden store. Thanks so much for helping!

If you are using a "free draining mix" it probably has few if any nutrients; so you have to add them. Most container growers use the "weakly weekly" method of feeding; i.e., a diluted fertilizer applied in water every week.

Could I just use my houseplant fertilizer until I can order some of that dyna grow I read about here? Things are going downhill quickly! I also should have mentioned that I'm battling aphids with Neem, could that have anything to do with leaves getting yellow blotches and falling off?