"I was beside myself in agony, but he fought to the end," Susan Williams tells PEOPLE

By Kara Warner
Updated November 05, 2015 08:00 AM
Kevin Mazur/WireImage

For all of the emotional pain and heartbreak Robin Williams‘ widow Susan Williams endured during the challenging last year of the actor’s life – a time when she and her late husband were fighting his then-unknown brain disease Lewy Body Dementia (LBD) – Susan tells PEOPLE that she immediately forgave her husband after he committed suicide, especially after finding out the extent of his suffering living with undiagnosed LBD.

“I completely forgave him, I completely understood,” Susan says. “I was beside myself in agony, but he fought to the end and I didn’t know what we were fighting, but I knew we were fighting hard.”

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With the help of neuropathologists and other medical specialists, Susan says she’s taken the past year to try and understand LBD and how it affected her husband. In now knowing what she does about the debilitating effects of the disease, Susan says his behaviors leading up to and including his death make sense.

“Everything has made perfect sense,” she says. “As painful as everything and this has been, I just keep following the next right thing and looking for the signs.

“I don’t think those kinds of wounds ever actually heal,” she continues. “You just kind of learn how to manage them better and that’s okay.”

Susan hopes that in speaking out about Williams’ tragic final days and specifically LBD, she’ll be able help raise awareness for the disease.

“I can’t help but think that there’s some big plan and that Robin and I are a small part of it,” she says. “We fought beside each other and we gave it our best.”