The easiest way to deal with the green poo issue is to use one boob for all feeds for either a couple of hours, or until it feels soft and empty, or until the other one is uncomfortably full. And then switch.
You also need to be aware that bubs can "feed" for lots of reasons other than hunger - being able to suck on a warm mummy makes them feel better. And they control their sucking so that when they aren't hungry they don't actually eat that much.
So the agitation may not be hunger-related at all - try a walk outside, or rubbing her tummy gently or playing some music! I had to accept that crying as though the world was ending for a couple of hours a day was just something my bub did for the first few months - he grew out of it though.