Try writing acetic acid as HAc. That'll be less confusing, and that's how I usually see it abbreviated in acid-base reactions. If you write it this way for acid-base reactions you won't get confused.
HAc + Ba(OH)2 --> H2O + ________
H+ + Ac- <- That's your acid as you know.
2OH- + Ba2- <- That's your base as you also know.