I planted a little lime from a local nursery a little over a week ago, and it's looking thoroughly unhappy. What started as a few yellow leaves at the base has now gone to full yellowing at the center and some brown spots/holes in the leaves. I thought maybe it was drainage issues since I only watered once (though heavily) immediately after planting, and this started developing within a few days. I checked the soil at that point and it was dry, so now I feel it's not drainage (nor over watering), though I can't be certain. (Yes, I have given it more water since then!) Could it just be transplant stress? It was under a shade tent at the nursery, and now it gets a few hours of morning sun, then shade, and then 4-5 hours of late afternoon/early evening sun. (Though the leaves don't feel dry like I would expect if it were scorched either?) I'm a bit dumbfounded as to what to do. Any opinions would be appreciated.

Also, the soil was quite compacted (new construction) so I rototilled it, mixed in about 3" of compost to a depth of about 5-6", and than dug the planting whole and mixed in some more compost and some miracle grow moisture control garden soil...probably about 1/3 original soil, 1/3 compost, 1/3 MG soil...I would've liked to till /amend deeper but I wasn't sure how deep the drainage pipe is and I didn't want to hit it, so I settled.