Woman shares warning after 40-year-old husband dies on 6th wedding anniversary

A woman is sharing her story after going from preparing to celebrate her sixth wedding anniversary to, just days later, planning her husband's funeral.

"I want people to know that life is short and to be good to one another," Karen McNulty, of Seaford, New York, told " Good Morning America ." "Show up every day for the ones you love. Don’t take those small moments for granted. Just be good to one another."

McNulty, a 37-year-old teacher, was just days away from celebrating her sixth wedding anniversary with her husband, Dominic McNulty, last August when she said he texted her from work that he wasn't feeling well.

Later that same night, he started vomiting and developed a fever, according to Karen McNulty, the mom of a nearly 3-year-old son, Dominic Jr.

After some improvement, Dominic McNulty's condition quickly worsened the next day, and Karen McNulty noticed his arm had gone totally limp.

Concerned, she said she convinced her husband to let her take him to the hospital, where she said he walked in on his own, without any help.

Just one day later, on the couple's wedding anniversary, Aug. 25, Dominic McNulty died at the age of 40, according to his wife.

"We thought it was just a stomach bug," Karen McNulty said of her husband's initial symptoms, adding that she later learned he had died of multiple organ dysfunction syndrome caused by sepsis , which occurs when the body has an extreme response to infection, according to the U.S. Centers for Disease Control and Prevention.

In Dominic McNulty's case, a bacterial infection had spread throughout his body, causing his organs to shut down. The symptoms of the infection only showed up two days before his death.

Nearly 2 million adults in the United States develop sepsis each year, according to the CDC, which notes that most people who develop sepsis have an underlying medical condition, like a weakened immune system or chronic lung disease.

Dominic McNulty, who loved sports and played on a hockey team with friends, was on immunosuppressant drugs to treat multiple sclerosis , a chronic autoimmune disorder he was diagnosed with in 2018, which further hampered his body's ability to fight the infection, according to Karen McNulty.

"I did a lot of detective work because, you know, you feel a lot of guilt, of what if I took him to the hospital sooner," Karen McNulty said. "I was told at the hospital, even if I took him a few days before, it would have been the same outcome because the infection was already in his system."

Symptoms of septic shock include confusion, fatigue, rapid heart rate, high or very low temperature, chills, lightheadedness and pale arms and legs, according to the National Library of Medicine.

Karen McNulty said she was left devastated by the sudden loss of her son's father and her beloved husband, who was otherwise healthy and planning for the future.

"It's that feeling of waiting for him to come home. His shoes are still by the front door. His toothbrush is still here. His clothes are hanging in the laundry room," she said. "You wake up every morning with a pit in your stomach, and you go to bed every night with a light on, and maybe this was all a bad dream."

Not wanting to lose the memories of her husband, especially those of him with their son, Karen McNulty began sharing videos of them together on social media , from running the bases on a baseball field together to playing with toy trains and digging in dirt outside.

"The thing he was most proud of was being a father to our son," Karen McNulty said. "The hardest part for me is that my husband and my son are robbed of time together. My husband was such a hands-on father ... I'm glad I have those moments captured."

The video memories of her late husband and their son acted as a sort of "journal" for her to work through her grief, she explained.

In July, Karen McNulty shared a video explaining the cause of her husband's death. The video has since reached over 9 million views on TikTok.

She said she hopes the video not only raises awareness about sepsis, but also encourages people to hug their loved ones tighter and live each day to the fullest.

"Every day I wake up for our son and I try to give him the best life possible because I know that's what my husband would want," she said. "If you can find a love and have a family, that’s the best thing in the world."