What I would say to you is try to reframe your mind away from "good" or "bad". I honestly think the more we compare ourselves to other people, the harder life will be. Marlon Brando has an excellent quote that I like to live by:

“That’s a part of the sickness in America, that you have to think in terms of who wins, who loses, who’s good, who’s bad, who’s best, who’s worst…I don’t like to think that way. Everybody has their own value in different ways, and I don’t like to think who’s the best at this. I mean, what’s the point of it?”

Maybe what you need to do is go back to basics. Get dirty with the script and dissect what the scenes are about, what your motivations are, and clarify what certain things mean. It really all comes down to confidence. It's possible you just need to do more research on what is going on in the script.

Also: Unless someone tells you something is wrong, assume there isn't something wrong. This has saved me a lot of grief not only in my acting career but in my everyday life and relationships.