Student or Learner
My heart was leaping around in my chest, and it was all I could do to keep my powers under control.
Cal appeared at my elbow, and it was all I could do not to jump guiltily. "
all I could do ??
It took all of my energies to do this (or not do this).
When that little girl was so mean to my daughter, it was all I could do to not reach out and slap her face. (It took a great deal of effort to contain myself and not do it.)
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.