As someone upthread said, other peoples' financial situations are a mystery. That said, some of your friends with the much larger diamonds may be wearing CZ, lab-created diamonds, lesser color and clarity diamonds, be in debt up to their eyeballs, because of the rings they are wearing or who knows? You may be feeling like you need to keep up with people who are barely keeping it together financially themselves. They MAY be able to afford what they have, they may not be able to afford it at all.
I am older and at this point I realize that things are not always as they seem. I know people, who have told us, that they are stretched financially, even though, everything looks great from the outside. I can think of a few people who I suspect are stretched very tight, because they spend more than they make, trying to keep up appearances.
You aren't spending more than you make, but you may be trying to keep up appearances with your friends. I understand there can be some competitiveness that goes on between friends, but frankly I would rather be the couple who looks like they don't have as much, but who are really in much better financial shape. Once you start trying to keep up with The Jones's, it's a never-ending game. There will ALWAYS be someone with more than you. Always. It's a no- way- to -win game.
I have several lovely rings. I have been married a long time. And now, more often than not, I wear a plain gold band by itself or pair it with a 1/2 carat diamond. I have larger, more expensive rings, I have diamond wedding bands, but I rarely wear them anymore, only once in awhile. It just doesn't matter. I have been married nearly 40 years...THAT matters more than how big my diamonds are or how expensive my wedding band is. My marriage and my family are what matter. The rest is gravy.
If you have a good husband who loves you, you are the richest woman in the world.