I planted this tree about 3 years ago. When we bought it at the markets, it was about 4 feet tall (now its over 10)- so it was developed and steady but with no fruit.
I keep supplying it with manure and epsom salt (with an occasional spoonful of brown sugar). Last year, it flowered well, but none of the flowers turned to fruit. This year, we see very little lemons but they keep dropping. This is a picture of the bunch of flowers and a itsy bitsy lemons :
https://imgur.com/a/7o58aM9
Cheers
Cutting the top to stop it growing would be a start and hand-pollinating the flowers with a paintbrush might help if it's not a self-pollinator.