Mexican Lime, fruit falling off, why?

People,
Brand new here. Fist post etc. I enjoy gardening and general landscaping but, I'm not very good at it. About 60+ percent of what I plant doesn't seem to want to take. I've put soil amendments and followed instructions on what ever individual plant I'm planting at the time but, many times, no luck. Sometimes they take and do well. Other times, just not sure.

Anyway, I do have one question while I'm here for the first time. We have a Mexican Lime in our back yard that has some mega-thorns on it, (if you're in the same zip code, it will bite you) and I've trimmed it back all the way to a stub sticking out of the ground about a foot, because I was intending to take it out but, I didn't and it's back. ln fact, it's about 8-10 feet tall. After trimming it that far down, it didn't produce any fruit for a couple of years but, it's recently changed and it doing OK in the fruit producing area. But, the question: During this time of year, the limes keep falling off the tree, I'm watering about every four or five days and the leaves seem healthy for the most part.

Some of the leaves have a little curling and look a tad wrinkly but about 90-95% of the rest of the limbs and leaves are fine. Am I watering too much or, not enough or ?

Our local temp at this time of year is around 70-80 plus or minus. We've had a few warm days in the last couple of months like, around 95 plus. What ever you can help with here would surely be appreciated. I have two dwarf orange trees, a dwarf Lemon and tangerine tree all within about 15-20 feet of this lime and they don't seem to have any of their fruit falling off. All of the fruit at this time is green with the exception of the Mexican Lime, many of them are yellow.
Scott