Saving Mira by Rhiannon Lee

Crushed under the surge, I fell to my knees, abandoning my struggle in the hope that the sheer magnitude of power channeling through my body would be enough to kill me.
Even at the end of days, escaping the past was impossible. In the blink of an eye, over half the world’s population was wiped out and Mira lost everything dear to her. In the face of crippling guilt and her struggle with depression in the aftermath of the ruined world that she helped create, she isn’t sure there is enough left to make life worth living.
White-hot pain like I’d never felt before licked every inch of my skin. I tried to cry out, but my throat felt squeezed.
Resigned to an uncontrollable fate, Mira barely scrapes by day to day. Although her furry companion, Hank, keeps her marginally grounded, he cannot stop her inescapable nightmares that plague her with reminders of her irreparable actions. And as if that wasn’t enough, each morning brings a murder of irksome crows and their gifts to her stoop that constantly force her to relive fragmented recollections of who she used to be.
If I could just save them! I kept pushing until I had nothing left to give, and with a final gasp I fell onto the ground, and everything went black.
When an ominous note is left at her hideaway, however, Mira can no longer live in anonymity. After a chain of life-altering revelations forces her to go on the run, can she learn to trust herself and her magic again? And can she do so while relying on three irresistible brothers who claim they want what’s best for her? Amidst a race against time, Mira must not only uncover who is responsible for tearing her from isolation, but whether or not she truly has the power to protect what is left of a dying world, even if it comes at deadly costs.