"How do we know for sure if a thought and feeling is based on our Ego or Source?"
When you think you know what it is that you want then keep asking "Why, Why, Why do I want it?"
When you get to your bottom line answer, it'll be clear to you where it comes from. And yet, feed your ego if that's what feels right. Why not have it all?
Ego is not bad. Ego is personal preferance. You are Spirit AND human.
Worthiness is having what you want, not having what you think others think you *should* have. The feeling place decides it all.