The 22-year-old model returned to social media Saturday following negative comments about Bieber, her job and other "positive" aspects of her life.
"Being off of Instagram is the best thing ever. Whenever I take breaks from it I feel so much better, so much happy as a person... the second I come back on I get immediate anxiety, I get sad and I get worked up," Baldwin wrote on Instagram Stories.
"It's hard to focus on your well-being and mental health when each time you open Instagram someone is tearing apart your job, or your relationship or essentially any of the things in your life that are positive," she said.
Baldwin called for people "to express more love and encouragement" instead of "tearing people down and judging." She said the world has "enough, hatred, hurt and pain as it is" without adding more online.
"The last thing we need is more negativity, hate, and division," the star wrote.
Baldwin and Bieber are longtime friends who announced their engagement in July. Bieber confirmed in a post in November that he and Baldwin had quietly married.
"Happy late thanksgiving to everyone. First thanksgiving as a married man, first time hosting thanksgiving. First time both sides of the family has come together," the singer said.
Baldwin and Bieber were spotted shooting a magazine cover together in Los Angeles last week. Sources told Entertainment Tonight the couple will appear on a new cover of Vogue and discuss their relationship in the interview.