Well, you're right. It's not easy to find a good balance in life. That said, I'm not sure if "being good" is something we choose all the time. Sometimes we have the choice, others we're forced into a difficult decision.

While we cannot accept deliberate aggression from others, there are moments that is simply better let it pass. Every decision holds a mix of inner fight between morals, dogma and conscience. But this is philosophical, sorry I'm going too far lol

Helping others is nice, I think. I like to do it sometimes. But some people do not deserve it, and we must understand and be prepared to not expect any recognition, it doesn't matter much in the end. Anyways, don't let the "good guy" in you die completely.

Also you talk about creating a false persona, that is really bad, I found myself in this situation many times as well. But being truly you requires some effort from time to time, and this is the lesson we learn.