LOMA LINDA, Calif. — “This is your life,” the doctor said. “You’re a quadriplegic.”

When she heard the news, Kim Gervais broke down. The tears rolled out, and her daughter clasped her mother’s head, overcome by her own inability to help.

Then came Ms. Gervais’s trip home to Southern California. And here she was, three weeks after the shooting, strapped into a wheelchair at a rehabilitation clinic, toughing it out with a physical therapist and straining to drink from a sippy cup as her toddler grandchildren looked on.

This is the road after Las Vegas, after a high-stakes gambler named Stephen Paddock hauled powerful weapons into a gilded casino and opened fire on a country music festival below. The journey — as the survivors of so many other American mass shootings will say — is one full of chronic pain, fights with insurance, ruined marriages, lost jobs, anguished parents and children, and the injustice of being forced into a new identity: victim.

And this time, with 58 people dead, at least 161 pierced by bullets, and more than 20,000 concertgoers from around the country left to soak in the memories of that night, the web of trauma spans from coast to coast, linking the casualties of this attack with those of all the others. San Bernardino. Aurora. Orlando. Newtown. And on and on.