Machine Gun Kelly got vulnerable in his new track “Don’t Let Me Go.” The song details the struggles he endured growing up and nowadays, with one lyric referring to his and fiancée Megan Fox’s pregnancy loss. “How do I live with the fact that my hand wasn’t on her stomach when we lost the baby,” the Grammy nominee, 33, raps in the tune, which debuted on Wednesday, February 21. This isn’t the first time he’s mentioned the tragedy, as he indirectly did so in his song “Twin Flame.” When playing the track live at the 2022 Billboard Awards, he dedicated part of the performance to their “unborn child…