Hi Judy, a little late to your question here but my experience with the mealycup salvias has been they are pretty much short-season annuals here. They last 3 or 4 months for me. Other salvias are much longer lived.
Did you try potting up your plant? If the potting soil had dried out (which (sadly) often happens with clearance plants) it can become like a brick and not absorb water again unless you let it soak for a couple of hours. Then, I'm sure it will appreciate some new room for roots to grow and it might give you a couple more months of pretty flowers. Break up the root ball gently, trying not to tear any roots, before you put it into the new soil.