No, you didn't put in too much effort. You just did your best (I hope). Don't feel that it is a waste or anything. I attained an ATAR of 82.85 and I want to get into policing at UWS which requires 69.4.
I got 13.45 above my required entry score, that's not considering i could've gotten under the required entry and also get bonus atar points.
But the course i want to get in is what i want to do, and i dont care whether it matches or is close to my ATAR or not, I'm not changing my mind about it. I'm just glad i received a good result which lets me do what i want. Just try and appreciate what you got and be proud of yourself that you're now able to do what you want. Besides, having a higher ATAR makes you look good (for now anyway) - yes, after awhile nobody is going to care anymore.