Guitarist Todd Wisenbaker, who has collaborated with Ryan Adams, is one of a number of musicians who have condemned the singer-songwriter after seven women alleged emotional and verbal abuse and harassment in a New York Times investigation published last week.

Actor and musician Mandy Moore, who was married to Adams, and musician Phoebe Bridgers, who had a relationship with him, were among the women who spoke to the Times, alongside a fan who says she was underage when he began to send her explicit messages online.

Adams has described the report as “upsettingly inaccurate … some of its details are misrepresented; some are exaggerated; some are outright false. I would never have inappropriate interactions with someone I thought was underage.”

In an Instagram post on Tuesday, Wisenbaker said speaking out was “incredibly hard”, and that he was “actively afraid for the safety of my family”.

Wisenbaker has performed live with Adams, played on his cover album of Taylor Swift’s 1989, and was recording new music with him last year, according to NME. He said he “recently learned that pretty much everything [Adams] ever told me is a lie upon a lie upon a lie”.

“There were times when I chose to believe his insane version of the truth because it was easier than believing that anyone is capable of being this much of a monster. It’s sickening and embarrassing … my life has become a complete shitstorm of someone else’s utter delusion.” He posted the message on Instagram with the caption, “Ryan please get help.” Adams has not commented on Wisenbaker’s post.

Adams produced the latest album from La Sera, a band founded by Vivian Girls’ former bassist Katy Goodman, which Wisenbaker, her husband, plays in. On Tuesday, Goodman also posted on Instagram, “Believe the women who have told their stories about Ryan Adams.”

After the Times published the initial report, an unnamed law enforcement official told the paper that the FBI’s Crimes Against Children Squad is investigating whether Adams committed a crime by engaging in allegedly sexually explicit communications with a teenage girl.

The Times report claims Adams sent the woman, identified as “Ava”, more than 3,000 messages over a nine-month period when she was 15 and 16. The Times reported that it reviewed the messages, which it claimed included requests for explicit photographs and repeated pleas for Ava to tell him she was over 18. Ava sometimes told him she was, but never showed him ID. (“If people knew they would say I was like R Kelley lol,” it is claimed he said in one message.)

Adams’ attorney Andrew Brettler said: “Mr Adams unequivocally denies that he ever engaged in inappropriate online sexual communications with someone he knew was underage.”

On Monday night, Mandy Moore appeared on comedian Marc Maron’s podcast WTF, where she revealed more about how her “entirely unhealthy” marriage with Adams affected her.

“I was living my life for him … I had no sense of self,” she said. “I felt like I was drowning. It was so untenable and unsustainable and it was so lonely. I was so sad. I was lonely with him.”

Since the Times story came out, other musicians have spoken out on social media. Jenny Lewis, who has collaborated with Adams, said on Twitter: “I am deeply troubled by Ryan Adams’ alleged behavior.”

Adams’ collaborators Catherine Popper, who has played with Ryan Adams and the Cardinals, and Natalie Prass, who has toured with and reportedly dated Adams, have also tweeted.

Last week Variety reported that the first of three new Ryan Adams albums scheduled to be released this year, Big Colors, has been “put on hold”. Pre-order packages which were listed on the website of the Pax-Am label, which Adams owns, have since been deleted.

The amplifier company Benson Amps, which had been collaborating with Adams on a signature model, announced it was no longer moving forward with the development of the product, saying it was “saddened and surprised by the recent allegations”. Walrus Audio and JHS Pedals have both pulled Adams-branded products, and a number of American radio stations have removed his music from their playlists.