Jessica Simpson Responds to Fans' Concern After Starring in Advertisement

Jessica Simpson is responding to some serious concerns from her fans ... after being featured in an ad online that many saw as anything but normal.

Jessica starred in a new Pottery Barn Kids clip last week ... where she showed off her 3-year-old Birdie's room -- showing how the company's collection brought the place together.

Seems harmless enough ... but the comment section quickly filled up with concerning messages -- with many asking if she's ok, and one even writing "blink twice if you need help Jess." Some saw the performance as forced, with the speech just feeling off.

The 42-year-old singer responded to the noise Sunday night ... posting a clip of herself singing in her studio in order to "ground myself and heal" -- adding, "peoples' comments and judgments can still hurt deeply with their incessant nagging."

She doesn't directly call BS on the worrisome fans' fears, but adds, "The most important thing I have learned through the last 5yrs without alcohol being a guard for escapism, is that I CAN and ALWAYS WILL get through it."