Jessica Simpson is opening up about sobriety and songwriting. In a cover story with sister Ashlee Simpson for The Cut, the "With You" singer spoke about songwriting and how drinking impacts the process. Jessica said that in 2016-2017, she was writing in Los Angeles "with some of the biggest hitmakers." She explained, "I have songs from those times that I never released because they just didn’t feel like me. Every time I would write, I was a little afraid of myself. It was almost too much, especially because I was drinking at the time." "But once I gave up the alcohol, the fears just diminished," Jessica, 44, continued. "They went away." The mother-of-three said once she stopped drinking, it became "so much easier for me to access myself artistically." "I’d thought the more I drank, the more cool I could be and find cool words that would rhyme, that wouldn’t be so expected. I overthought it when I drank." She found it "more empowering" once she took alcohol out of the songwriting process. "I started pulling out my old journals, which eventually became Open Book. I now realize the power of words put to music." Jessica has been sober since 2017. She celebrated her seven-year anniversary of sobriety in November. She would go on to write music in Nashville. Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer​​, from celebrity news to compelling human interest stories. The singer is releasing an EP titled Nashville Canyon Part 1 on March 21 and will be dropping the single "Use My Heart Against Me" on Feb. 21. "I'd wake up in the morning and write down poetry, lucid dreaming style," she told PEOPLE exclusively in February about working on the album, "and then bring that to the songwriting sessions." For "Use My Heart Against Me," Jessica said she "woke up with that lyric in my head." "It’s kind of craving someone that you want again and you don’t care if your heart is used against you – if it’s just for one night. Like, give it over, just for the experience again." Jessica's sister Ashlee, 40, recently gave PEOPLE an update on Jessica's music, calling her upcoming EP "delicious and yummy and honest." "I think the most important thing about being ready to strip your layers and be where you're at and meet yourself musically and as an artist, she's doing that and I'm very proud of her," she said in February. The PEOPLE Puzzler crossword is here! How quickly can you solve it? Play now! Ashlee added, "her music is great, I'm very excited about it, yeah. And I think everybody will love it." If you or someone you know is struggling with substance abuse, please contact the SAMHSA helpline at 1-800-662-HELP.