Heart of Stone by Andrea Cannon

Pamela has spent years building the wall that insulates her heart from the emotional roller coaster of life. A rocky childhood laid the footing for that wall, and no one has ever come close to penetrating it - that is until Alex came along. Suddenly Pamela is questioning her independent nature. Alex is not one to give up easily, but has he underestimated Pamela's stubbornness? It might take a miracle, or a catastrophe, to find out.