Yolanda Foster Is Not Great But She is Waging the War, According to Husband-Musician David Foster

Yolanda Foster's condition has not improved, according to her husband, musician David Foster.

Foster told reporters at the 2015 MusiCares Person of the Year Gala on Friday that the Real Housewives of Beverly Hills star, who was diagnosed with Lyme disease in 2012, has been struggling with the illness of late.

"Yolanda is truthfully not great," he said. "She's just waging this war and ... she's down right now."

The musician, 65, went on to tell PEOPLE that he tries his hardest to be there for his wife in her time of need. "I fail some days," he said. "You know, I get cranky and then I realize that she's got it 100 times worse than me. But I just do my best."

In January, Yolanda penned an emotional blog post in which she shared that she had "lost the ability to read, write, or even watch TV, because I can't process information or any stimulation for that matter."

David also mentioned that he wanted to be as supportive as he can, but she is just worn out and beats him to the ground. The Lyme disease is such a strange sickness as some people can get it and they can have it for a couple of years and they just fight it off like a cold. And for other people it brings them to their knees.

Despite the setbacks, Foster believes his wife of three years will bounce back. "She's a warrior," he said, "so she's going to beat it."

As for the couple's date on Valentine's Day, David said it's a dinner reservation and a showing of Fifty Shades of Grey.