Former Nickelodeon star Matthew Underwood says he quit acting after he was molested and sexually assaulted

Matthew Underwood, former star of Nickelodeon's "Zoey 101," opened up on Instagram Friday to share two personal stories of alleged molestation, sexual harassment and sexual assault he said he endured during his childhood and teenage years.

"When I was 12 years old, I was groomed and molested by my best friends' stepfather," Underwood wrote, saying the incident made him lose his best friends.

Furthermore, Underwood said he was again the victim of sexual harassment by a former agent.

"When I was 19, I was sexually harassed and then assaulted by my agent at the time, who had spent a decent amount of time building trust with me as a friend and mentor," he wrote.

He added, "This experience provoked my move away from LA and ended my pursuit of acting."

Underwood's comments were made in the aftermath of the release of the bombshell docuseries "Quiet on Set: The Dark Side of Kids TV," which investigates claims of abuse, sexism, racism, and toxic workplaces at some Nickelodeon shows in the 1990s and early 2000s.

"I'm sharing this with hope that some of you can recognize that just because a person doesn't shout from the rooftops that pedophiles are bad or that people can suck - that does not mean they don't have their own reasons for staying silent, good reasons, personal reasons," Underwood wrote.

"I have extreme empathy for anyone who has been taken advantage of by people they trusted," he continued, adding that he hoped people considered why victims may not always be willing to share their experiences publicly.

As for "Quite On Set," Underwood said he "never had a bad experience working on set of a Nickelodeon show," adding that he also "never had a bad experience with Dan," referencing Dan Schneider, the Nickelodeon producer at the center of many toxic workplace allegations put forth in the docuseries.

Underwood added that from his observations, he believes Schneider, the creator of "Zoey 101," recognizes some of his alleged prior misdeeds and would "like to believe he is fully capable of being a creator and coworker everyone can enjoy working with."

The former Nickelodeon star ended his post with a plea to the public to stop the pressure for him to speak out.

"...Please reconsider harassing other actors who wish to maintain their privacy - you never know who has already been a victim of the hell you're wishing upon them," he wrote in part.

In the caption, Underwood again reiterated his plea for peace from the pressure to speak out. He also clarified that his current agents were not who he was referring to in his allegations and thanked them for their support in helping him make his way back to entertainment.

Underwood, 33, starred in the hit Nickelodeon show "Zoey 101" from 2005 to 2008, playing Logan Reese. Last year, Underwood starred in "Zoey 102," a sequel film to the original hit series.

ABC News has reached out to Underwood for further comment via a representative.

After the docuseries was released, Schneider posted a response video.

"Watching over the past few nights was very difficult," he said. "Me facing my past behaviors, some of which are embarrassing and that I regret … and I definitely owe some people a pretty strong apology."

He also stated any scenes from his shows that come across as "inappropriate" or are "upsetting somebody" should be edited out, and had previously noted that all shows and scripts had been approved by network executives.

Nickelodeon severed ties with Schneider in 2018.

Nickelodeon has also responded to the series, with the network telling ABC News that while it "cannot corroborate or negate allegations of behaviors from productions decades ago, Nickelodeon as a matter of policy investigates all formal complaints as part our commitment to fostering a safe and professional workplace environment free of harassment or other kinds of inappropriate conduct," adding that it has "adopted numerous safeguards over the years to help ensure we are living up to own high standards and the expectations of our audience."