Impa:
To hear that her lover was insecure about their looks hurt her soul. She already had Zelda to deal with and now her lover. She would aggressively tell you how you are amazing and that she is grateful that the goddesses have bestowed you to her. You're great, you're worth it, you're awesome. Periodt.
Zelda:
Since she can relate in a way, she understands you more. You were insecure about your strength while she was also insecure about her potential. You both just support each other as you go through your phases. Whether it's holding each other, saying comforting things, or just even a gentle hand, you both support each other.
Mipha:
She was hurt when you said such things about yourself. But she would be as supporting and comforting as she can. Not to mention, she always says things in kind words, empathy, and care. Honestly, it's hard to be sad around her since she's so comforting, you were thankful to have her in your life, really.
Urbosa:
She would go mother mode again. She heard you were just insecure about, everything really. She'd give you advice, whether it's what you think about yourself, your looks, your strength, potential, iq, whatever. She would give you advice if you wanted to fix something. But if there's nothing that needs to be fixed, she'd tell you and be honest. (Thinking of that one scene from hunchback of notre dame of monster lines)
Purah:
She heard you were insecure about your smarts. She just straight up decided to annoy you with compliments. Every so often when your doing a project, she'd tease you but say how smart you were. This would happen too much and you ended up asking about it. She told you that she was just saying the truth, she said how your one of the best on her team, and that it was okay that you needed help. Pointing out that everyone, even herself needed help sometimes.