did you loosen the root ball when you planted?. which way does it face and where in Texas. if you don't loosen the root ball it will dry out and water will not get to it and azalea need shade it in Texas and i know Texas air is dry with 20-30% humidity wont do it need shade only need morning sun 2-3 hr. but if you live in east texas that a different story

Texas is not an ideal location for most azalea/rhodos. You may be fighting an uphill battle.

I actually live 1 mile from the Texas coast north of Corpus Christi. Our humidity is mostly from 50% up. The azaleas are in filtered shade and I did follow the directions for planting. My husband is from Georgia and wanted azaleas so I thought I would give it a try for him and they were beautiful until around April of this year. Maybe the accumulation of salt from the well?

that might not be good try rain water

If the well water is very alkaline - roughly above pH 7.5 - this could definitely be your main problem. If the well water contains other salts, the problems are compounded. Did the decline of the azaleas begin when you started watering? While not ideal, the soil pH seems ok. Even if you could collect rain water, inject vinegar or another mild acid into the water for the azaleas, it would probably be a losing battle. Sometimes it's best just to accept that there are plant families that will not grow where we are much as we would like them to.

April is probably also when it started to get hot. Loosening the outside of the soil balls won't have any effect on whether they take up and retain water or not. Do you see any azaleas in other gardens in the vicinity? If not that could be a hint.