My heart is afeared of all the secrets in my past, which could come back to haunt me 今日 (KYOU=today)
To be intimidated. Sometimes it is used the same way as more popular cousin 怖がる （こわがる）: to be scared. But often it connotes a very specific form of fear : to be cowed, scared into submission - usually used with things like political intimidation or domestic violence. To be scared into complying or obeying.
not just a coward ,but someone who does treacherous, trifling bullshit because they're a coward - like if they fight you they know they can't win fairly so they'll knee your groin, they're a 卑怯なmotherfucker.