Most Helpful Guy
I'm sure you are accurately describing your feelings. His problem with your expression of them is that, unless one is a bully or sadist, it is hard to have a balanced relationship with someone who does not feel confident enough to be a peer as well as a GF/BF.
The fact that his is mad means that he wants you to feel fully equal and open. Which, unless you are truly committed to a submissive role is exactly what you should aspire to. I would suggest that you really think through WHY you sometimes "do not feel good enough", perhaps trying to talk them through with someone REALLY trustworthy (friend or counselor).
By understanding what is going on with you in a more comprehensive way, you can express your feeling to him more clearly and you and the two of you can work to help you feel worthy all the time.
Most Helpful Girl
Never tell a guy you have low self esteem Bc the wrong one will just exploit it. Plus it makes you look weak.
You were uniquely and wonderfully made so you shouldn't feel that way about yourself. You are just as good as anyone else and no one is any better than you.