The 48-year-old actor took to Facebook where he poured his heart out on how his life had changed after the death of McNamara.
"I'm one year into this new life -- one I never even imagined, and I can imagine some pretty pessimistic and dark contingencies, some stomach-freezing 'what ifs'. But not this one.
"Last night I took off my wedding ring. I couldn't bear removing it since April 21st, 2016. But now it felt obscene. That anonymous poem about the man mourning his dead lover for a year and a day, for craving a kiss from her 'clay cold lips'. I was inviting more darkness," wrote Oswalt.
"Michelle brought me nothing but happiness. You see it in our faces... We lost someone who made us live better in the world. It would be an insult to them not suddenly live badly in this world," he wrote.
McNamara died in her sleep as a result of drug interactions with a previously unknown health condition on April 21, 2016.
Disclaimer: No Business Standard Journalist was involved in creation of this content