My potted lemon trees were recently brought in from the outside due to weather changes. Now, they are dropping leaves that have become splotchy and yellow/green. Prior to bringing them in I watered them well with a mixture that had coffee grounds in it. They are currently in my sunroom, but don't actually get full direct sunlight. The temperature does fluctuate in this room as its cold during the night and warmer during the day. Not sure what exactly has caused this sudden change. Please let me know if you can help me with a solution to the problem. Thank you in advance!

They are dropping leaves because of lack of sunlight. In the lower light of your sunroom, the trees are shedding the leaves they can't support anymore. The leaves are blotchy because the tree is harvesting nutrients before dumping them.