Holly bush is dropping leaves
The leaves are turning brown and are falling off. I don't remember this happening before. Is it dying?
This article outlines possible reasons for leaf drop: https://www.gardeningknowhow.com/garden-how-to/info/plant-dropping-leaves.htm
You've had a very hard winter, and it's quite possible your holly is suffering from this. Wait until spring is well underway, to see if there are signs of new growth. You can then cut dead growth back to where it is starting new leaves, or showing green tissue under the bark.