Chrissy Teigen has issued an apology to the people she bullied online in the past, while admitting that she was a "troll, full stop."

The former model recently came under heavy criticism after some of her resurfaced tweets revealed that she bullied multiple celebrities including Courtney Stodden, Lindsay Lohan, Farrah Abraham, and Michael Costello in their younger days. Several of the stars also came forward to admit that her hurtful tweets had a harmful impact on their mental health.

The 35-year-old returned to Instagram on Monday after a month-long hiatus, and said that these have been a "very humbling few weeks." In a lengthy apology which she also shared on Medium, Teigen wrote: "I know I've been quiet, and lord knows you don't want to hear about me, but I want you to know I've been sitting in a hole of deserved global punishment, the ultimate 'sit here and think about what you've done.'"

"Not a day, not a single moment has passed where I haven't felt the crushing weight of regret for the things I've said in the past," she added, noting that she is "truly ashamed" of her controversial tweets.

The author revealed that she is currently in the process of privately reaching out to the people she has insulted, and would like to listen to what they have to say even though they may not want to speak to her. She also noted that she has apologised publicly to one person- Courtney Stodden, but the latter recently said that Teigen never approached her privately.

Teigen added in her message that she admits she was a "troll," which she said stemmed from her need to be "accepted."

"In reality, I was insecure, immature and in a world where I thought I needed to impress strangers to be accepted. If there was a pop culture pile-on, I took to Twitter to try to gain attention and show off what I at the time believed was a crude, clever, harmless quip. I thought it made me cool and relatable if I poked fun at celebrities," she explained.

"Now, confronted with some of the things that I said, I cringe to my core. I'll honestly get sharp, stabbing pains in my body, randomly remembering my a–hole past, and I deserve it," she admitted.

The entire controversy erupted in March this year when Teigen decided to leave Twitter because of nonstop negativity, prompting Stodden to call her a hypocrite and share her old tweets where the "Cravings" author told her to take "a dirt nap" and "go to sleep forever." While coming out as non-binary in April, Stodden revealed that Teigen would even privately message them and "tell me to kill myself." Stodden was only 16 at the time but was constantly ridiculed for their marriage to 51-year-old actor Doug Hutchison.

After Stodden, designer Michael Costello came forward to speak against Teigen and revealed that she left him feeling suicidal after she labelled him a racist and blacklisted him in the fashion industry due to a photoshopped Instagram comment that he never made in the first place. Meanwhile, Lindsay Lohan's mother revealed that the actress as well as their family were deeply hurt after Teigen tweeted: "Lindsay adds a few more slits to her wrists when she sees Emma Stone." The tweet came at a time when Lohan had admitted to self-harming amid her battles with mental health, addiction, and intense public scrutiny.

"Teen Mom" alum Farrah Abraham also opened up about a hurtful tweet posted by Teigen in 2013 when the former had gone to "therapy publicly for sex-shaming and was working through her own depression, bereavement, and vulnerabilities." The tweet which was shared last month by Candace Owens reads: "farrah abraham now thinks she is pregnant from her sex tape. in other news you're a w---e and everyone hates you whoops not other news sorry."

John Legend Chrissy Teigen
Chrissy Teigen and John Legend attend WGN America's 'Underground' Season Two Premiere Screening at Regency Village Theatre on March 1, 2017 in Westwood, California Charley Gallay/Getty Images