Jess, don't be so hard on yourself, sweetie.
Listen, a lesson I learned a long time ago is this: This is the internet. An internet forum. You can't please everyone. What we say here comes across, mostly, as text on a screen. There's no physical element. No one sees your tears, your smile, your body language, your intent... none of that. And this site is... well, it's a volatile environment. Moreso than most other places there are folks who will take offense at things not meant to be offensive simply by virtue of the baggage we all carry around. Things which happen in our own lives colour our perceptions on how we view what others say. And there's an element of being very defensive, simply because a lot of us have to defend ourselves on a daily basis, to people who know no differently. And sometimes... it's hard to not be that way, you know?
It's not necessarily a reflection on you, Jess. People sometimes feel like they have to put their point across is all, even if it's off-topic, to air a grievance or just get out something that's been bottled up for a long time.
Please, just remember, sweetie, we're all struggling with a lot of emotion sometimes, and that can lead to... differences in world view, or differences of opinion. That doesn't make you a bad person, or give you any less right to say what you think.
Your purpose is just to be you. Same as it is for everyone else. *hugs*