I heard my younger sister say that I’m not handsome

Me and my two younger siblings and my mother were playing monopoly. During that I was laughing with my mom and mocking her “not that serious, we’re like friends and she knows it” and my younger sister who is 9yo got upset at me cuz I was mocking my mom. 15mins after, my mother was talking about me and I’m a handsome guy etc. and then she says to my mother “he’s is not handsome”

That literally broke me from the inside, I felt really insecure and fragile, I even felt that a part of my love to her went away.

I don’t know what to tell my self about this, not about my sister, she doesn’t care abt this as much as I do, it’s about how will I deal with this inside of me, even though I’m not that ugly til someone says that I’m not handsome, I feel really broken and I don’t know how to fix it. Just tried to convince my self that I’m handsome and I believe in my self, but the problem doesn’t get solved and it gets bigger in me til it reaches the side side of love and make me feel that I’m not worthy of the love that I have from other people even from my family and I only get love just out of pity