Hi Ashley, the advice Sue gave you is good. If the root ball was hard and dry, re-hydrating the soil will help to revive the plant. You shouldn't need to add new soil, as the old soil will expand when it takes up water again. Take note of how heavy the pot feels when the soil is well wetted, and in future when you water, be sure to heft the pot so you are sure the water was absorbed and didn't just whiz on out. If you're only watering once a week which is fine in winter but not nearly enough in summer, you need to make sure the plant is thoroughly wet each time. Increase watering as soon as you put the plant outside again, and keep increasing as the weather gets hotter or the root ball will dry out to a brick again. Citrus hate to dry out.
I must admit that I would have advised you to remove all the fruit right away from a plant that small. The first year you have a little citrus tree, it's best to let it grow lots more leaves and roots before putting it to the hard work of making fruit. So if it still has fruit coming along, I'd advise you to take it off, to allow the plant to recover and put its energies into surviving. Otherwise the plant will put too much into the fruit (survival to a plant means making seeds and completing its life cycle even if it kills the parent plant) and won't grow new roots and leaves for you. Putting it simply, leaving the fruit on may kill a stressed plant.
