I am happy, I get a little bit nervous at times about being “on the shelf”. I guess that’s why their comments cut so deep but it’s not something I’ve actively spoken about with them.
This worries me most about your post because if you are knowingly insecure about something, it is really shitty of "friends" to press on that button. It's nasty shit to rub on your friends sore point.
A lot of this is perspective and bear in mind in life people are most nasty and judgmental about what they themselves are insecure about - they are probably looking at you and wishing they had a bit of your freedom and feeling insecure they don't, so manage it by attack.
Making yourself feeling better by attacking others is well known as a bitch self-boosting tactic.
Like I said, it's perspective isn't it. The person I regard as the biggest "failure" that I know is someone who had a golden childhood of privilege (private school, great education, lots of extra curricular activities to a high standard), super-intelligent and high achieiving at school/university, got a good degree and was offered professional graduate training opportunities in places that some people would kill for, really wanted to make it as an actress and basically bummed around not getting anywhere pretty much only amateur acting, still thinks (now early 40s) there is a chance of sudden discovery (which although is possible for a woman in her 40s in that job is very unlikely), married a man with a good job and just became over-invested in her children because as an adult has never really achieved anything herself.
I think it's a sad, wasted life for someone with every life opportunity and so much potential. I know she feels bitter about her lack of work achievement and lack of income. It's very very sad and she isn't happy. Her husband is one of those who controls everything because he controls the money. She turns a blind eye to it and lives her life as if every breath of her children is to be worshipped.
That's just my take on it though. There would be women who looked at her and think her life is a huge success just because she's married, has a couple of kids and a husband who is financially comfortably off.
You probably need to spend a bit more time on the relationships boards here and read how miserable and unhappy and badly treated many women who are in relationships and marriages are. It's not happily ever after for everyone sadly.
So to answer you - no of course you are not a failure. Don't be insane!