Kelly wrote about her late husband Tuesday, saying it's felt like both "a week and an eternity" since his passing -- and the rest of her remarks were pretty emotional, even 2 years later.

She used one of the last selfies he took onstage for her post ... which, according to her, was a great example of him "doing what he loved to do…making people laugh…making people happy."

She continued, "I will forever be grateful that I got to share life with this extraordinary person for 6 years. What a blessing. And grateful I can look back on endless memories and photos and videos with smiles, laughter, and yes…still tears."

Kelly then reminded folks to "hug your loved ones," and admitted she's "blown away by the fact that Bob hasn't faded from all your hearts in the slightest."

She did the same last January, remembering her "brilliant, adorable" husband a year after he died ... saying, in part, "the gratitude I have that we have each other is immeasurable."

As you know, Kelly lost her husband at the beginning of 2022 ... after he was found dead in his Orlando, FL hotel room. Authorities determined he died from blunt head trauma, apparently falling backward and hitting his head.

There was an outpour of folks honoring Bob after his shocking death -- including his longtime pal and "Full House" costar, John Stamos, who wrote, "I am broken. I am gutted. I am in complete and utter shock."

Celebs came out in droves to send him off at his funeral ... including John, Norman Lear, Dave Coulier, John Mayer, Jeff Ross, Ted Sarandos, Dave Chappelle, Kathy Griffin, Chris Rock, Judd Apatow, and many more.