Can anyone help me with my question?

I have a small Meyer Lemon tree that was doing very well until the past 2
weeks. The lemons are starting to lighten ,however they are spliting and
falling off the tree.
I am new to Florida and very new to growing citrus trees for personal use.
I did have a problem with leaf miner a few months back and got something
from the local nursery. Now I have this problem.

Any suggestions will be greatly appreciated.

Thank you