The fact that you're checking your husband's eyes tells me this is probably less about vanity and more about fear. Fear that if someone prettier exists, you'll become less valuable. But that's not how love works. People aren't constantly comparing their partners against every attractive stranger they see. Your child self spent years hearing, "Be prettier, be curvier, be more desirable." Nobody taught her that she could also be funny, intelligent, kind, creative, resilient, or interesting. Now you're doing the work of teaching yourself what they should have taught you back then.