By Randi Kaye and Scott Bronstein, CNN
Phoenix (CNN) -- Mike Rioux can't go to the grocery store without making a list, even for a single item.
He can't drive without gripping the steering wheel so hard his knuckles turn white. And he can't stand any longer than 30 minutes because of severe back pain.
This is Rioux's life after Afghanistan, where firefights and a roadside bomb blast left him with a traumatic brain injury and post-traumatic stress disorder.
His ears still ring from the explosions. He suffers from vertigo, headaches, insomnia and nightmares. He has terrible anxiety, evident in an interview with CNN -- Rioux could hardly sit still, and his memory loss and inability to concentrate meant questions had to be repeated at times.
"I need to discover who I am again," he said.
VA backlog 'plagues' veterans nationwide
How veteran voters could swing election
Little-known military benefits
New economic realities for military vets
As a staff sergeant in the U.S. Army, Rioux most recently was deployed in 2010 to one of the most dangerous spots in Afghanistan. There he survived firefights and blasts and witnessed much carnage in Paktia province, near the volatile Afghan-Pakistan border.
After returning home, Rioux faced a much different battle, one that neither he nor his wife, Maggie, expected.
Confusion is 'monumental'
The Department of Veterans Affairs said it is on track to process 1 million disability claims this year.
With the war in Iraq over and the one in Afghanistan winding down, the VA is sorting through a backlog of more than 860,000 disability claims from American veterans. More than a quarter of those vets -- 228,000 -- have been waiting for a year or more.
Rioux has been trying to get his disability claim fully processed since January 2011, shortly after he returned from Afghanistan.
The litany of delays includes lost paperwork, long wait times for appointments and erroneous lab results. At one point, a doctor prescribed him medication for a bladder infection he didn't have; he'd never given as much as a urine sample.
Because of his debilitating injuries, neither Rioux nor his wife, Maggie, is able to work full time. Rioux said without his wife's care, "I'd be in the fetal position. I'd be curled up in a ball. I couldn't do it."
He can afford it, she can't: Couple's health care dilemma
The Riouxes and their 23-year-old daughter, Alex, are living at his mother's home outside Phoenix. Maggie and Alex share a bedroom, while Mike sleeps on the living room couch every night.
At 51, he said that makes him feel ashamed.
"I feel low," he said. "How can I support my family, let alone ... keep a roof over their head so that my daughter can have her own room? My wife and I can't have a bed to sleep together? We're on couches. We sleep separate. ... That hurts a lot. I miss her."
Part of the problem, the VA said, is that many veterans are returning with severe and complex mental injuries. These veterans file multiple claims, far more than ever before, and sometimes they file incomplete paperwork.
The backlog also increased when hundreds of thousands of vets were finally allowed to file claims for Agent Orange and Gulf War syndrome. Last year, the VA said it paid out nearly $5 billion in compensation.
In August 2011, the VA told Rioux his claim was in review and, four months later, he was told to expect a decision by the end of the year. None came.
Both he and Maggie wrote numerous letters seeking help, including one to first lady Michelle Obama, with a copy sent to Veterans Affairs Secretary Eric Shinseki.
Three months ago, the Riouxes finally heard from the VA about his claim. It rejected coverage for his traumatic brain injury, granting him limited disability coverage that amounts to about $660 a month.
Mike Rioux\'s combat tour in Afghanistan left him with a traumatic brain injury and post-traumatic stress disorder.
Mike Rioux's combat tour in Afghanistan left him with a traumatic brain injury and post-traumatic stress disorder.
Attempts to get full disability coverage have left the Riouxes often lost in a morass of red tape and confusing policies at dozens of offices in various veterans medical centers.
"That is trademark VA -- that you get answers, and then a different answer from the same building, but a different floor or a different office," Maggie Rioux said. "And the confusion that ensues is monumental."
The Riouxes are not alone. Two-thirds of the 860,000 applicants have been waiting longer than the 125 days that Shinseki set as a goal for processing claims. On average, the VA said veterans wait more than eight months -- 256 days -- before their claim is resolved.
CNN interviewed 16 veterans for this report, all of whom recounted monthslong waits to get a simple evaluation of their disabilities. Many said they had not received prompt help for serious mental health issues. One vet said he called a VA suicide prevention hotline, was told he would be called back, and a return call never came -- a situation the agency said never should have happened.