The Dragon’s Mate by Serena Simpson

Kisame was an explorer fighting to explore The Interior, a part of their world that was off limits. This was where the last war happened; it destroyed their lives and their past. She wanted to understand what happened there. She was taught like everyone else it was aliens that came to their planet, although she never believed that history. Finally, she was going to be allowed to explore the forbidden.
Rilan was in hibernation. One day he was the ruler of the most powerful empire on Terra, now he was asleep. A presence he never felt before touched something deep within him waking him up. The pain and anguish he felt waking to an empty world held him in its grip until he saw her.
Kisame realizes she walked into a conspiracy older than the war that had been fought. Rilan realized that his people were suppressing and denying their ability to shift into their dragon forms. A battle would be fought, but it would begin with them learning that there was no future unless the two of them allowed love to bring them together.
This time there may be another war brewing. If so, it meant death for all and not just the dragon shifters.