Apologies if I read their or your statement incorrectly.

Bitter defined as 'a sense of unjust treatment', is absolutely correct, but 'angry, hurt, or resentful'... nah, none of that.

In fact, quite the opposite, I'm extremely happy about my decision to not have children.

I'm just not a fan of people who think that it is the most meaningful thing I (or anyone else) could ever do.