I totally agree. We do compare to others. I don't necessarily think it is bad either. I get inspired by others, learned to put on makeup from others, how to act in tough situations from others, etc.
I think what is important is to hold on to your own confidence as your own person. Maybe you think you could be better? GREAT! If you didn't, then that would be quite boring, and leave little room for personal growth.
Acknowledging this is good. However, one of the hardest things is to believe your partner when they say you are special.
1) find a partner who you trust, and 2) trust that partner.
Finally, trust yourself.