There must be some azalea people on here somewhere and maybe they will chime in.In the meantime,I would transplant into a larger pot with some acidic soil.Plain Miracle grow without the water crystals would be fine.Fertilize,when you fertilize,with tomato fertilizer.Most of these plants come from the nurseries planted in almost pure peat.That stuff is terrible for not taking up water.In other words,you take the plant out of the small nursery pot and move rootball and all into a larger pot with decent soil.The good soil holds water fine but the peat doesn't take it up so it isn't available to the plant.If you transplant it now,carefully remove about half the peat surrounding the rootball so those roots can get to some better soil.
Wish I could be more help but here all the azaleas grow in the ground.
