Was gifted a potted outdoor lemon tree, it was a little yellowing/brown when we got it and has only gotten worse… at first I thought underwatering so I pruned some dead leaves and diligently soaked it ~once a week/every 10 days, but it does not seem to be improving and maybe getting worse?? Finally got some citrus fertilizer 3 days ago and worked it into the top of the soil before watering, still no changes yet… any advice? It gets full sun, 50-60* weather with some wind, high humidity in this area so I am afraid of overwatering.