Hi Lauren!

A soil test wouldn't hurt and could give you more insight into any possible nutrient deficiencies. You can find more information about soil testing here, including the list of labs that offer it and instructions on preparing the soil samples. You can try again to reseed your lawn, but first remove the thatch (dead grass layer), so the seed can get into the soil. But this is not a guaranteed fix. We see no indication that the lawn issue would harm the azalea. 

In Maryland, we're in a climate transition zone which is not favorable to growing lawn grasses. I actually grew up in Anne Arundel County and all of our yards looked like yours! Spotty grass growth and bare patches, and no matter how hard we tried, the grass just never took off. This could be an opportunity to look into lawn alternatives, especially using our native plants. Check out the case studies with photo examples for inspiration. 

Your yard also looks like it's on a slope and the deep root systems of native plants will help reduce your runoff and erosion. 

Jamie