About the only evergreen shrub that will fit into that very narrow space is something like boxwood, which can be sheared into a tight, dense form of your choice and size. But boxwood along the east coast have some serious issues with blight, so that may not be a great choice. You could research and seek out some of the most resistant varieties if you can find them. Or you could substitute with Japanese holly, a boxwood look-alike. A bit more adaptable to different planting conditions and grows a bit faster but regular pruning of anything will be a requirement to keep size in check for that tight siting.

thank you!