Yes,you sound very insecure, so stop having this mindset, lots of women actually look great when getting a bit older , and manage to have more confidence about themselves, and how they look etc. If you have the mindset, that men may look at younger women, well they will do, its always been the same, but is quite meaningless really.
To be honest, I have often seen men in their thirties, who have gone to seed, with blobby and paunchy bodies, who are badly dressed, and bald to boot,, who's wives /partners always make a big effort to look good.
No use at all, thinking the way you do,. if you have a good relationship witth your Husband, that's all that matters..