What is wrong with my shrub?

On first looks like it was cut back to much. Take picture to your local nursery to get more information for your area and project.

Trim off the dead branches and then keep it watered. A little plant fertilizer might help it along if the soil is depleted of nutrients.

Regarding the dead areas in the lower part, the shrub should be trimmed to be narrower on top than the bottom, so light can get to all of it. The spots look like a leaf disease, so taking a branch of those spotted leaves along to the nursery is the thing to do, so they can help find a treatment for it.

The above recommendations are right on but I would also take out some of the branches in the center of the shrub to let air get through. I'm not sure if that is black spot or what but plants need to get air through them so they don't have moisture sitting on the leaves and causing damage. A local nursery could tell you the best info on the problem.

If its only affecting the lower part of the bush then you have a blight going on. Go to your nearest nursery with a clipping and they'll recommend a good fungicide to use.

Good luck!

Black spot for sure. It needs a good trim, yes cut it way back and it will only be sticks. Clean out al of the dead wood and all of the area around it. Give it a good fertilizer with vitamin B, super thrive is great(Lowes).

i would do it before you are in danger of frost in your area.it will look bad for awhile, but should all grow back nice. Good luck

Part of the problem could be that the bush is not getting sufficient water and nutrients because the soil underneath the branches is clogged up with dead leaves and is packed down too hard. As Dorothy suggested, clean out all the old stuff that is under and around the bush, rake up what soil is left to aerate it, and feed it the right kind of fertilizer.

It looks like black spot fungus to me (and perhaps powdery mildew). Take a better pic of the bottoms so the nursery can see if there is color on the stems. If it looks green, greenish-to-white it is powdery mildew. It could also be whiteflies.

Back to what you DO have - black spot fungus. "Black spot fungus begins to develop in the spring when temperatures reach into the sixties and the garden has been continuously wet for six to nine hours."

https://www.gardeningknowhow.com/plant-problems/disease/black-spot-fungus.htm

You can spray with Neem oil, a natural fungicide from the nursery, or mix a heaping tbs. of baking soda with a gallon of water in your sprayer & add a dash of Castile soap or horticultural oil.

You should take a deep breath and be brutal, cutting away all the areas that are already affected with black spot. Dispose of the debris in a garbage bag, sealed tightly to keep the spores from infecting other areas of your garden. You should spray the entire bush - the tops and bottoms of all leaves as well as the stem and branches - as often as every 5-7 days for 1-3 treatments to see the best results. Keep an eye on things and watch for this in the spring especially.