It's easy to feel like you've offended people so badly that you can't show your face again, but the feeling doesn't mean you have. I've felt like that several times in my short stay here already (and I'm sorry for the tone of some of my posts toward you). At one time a month or so ago I went through and deleted a bunch of my posts and resolved to leave so I wouldn't bother anyone... and more often I'll just avoid a thread where I don't like my last reply.
It's never as bad as it seems, though. What seems like a big deal usually isn't, it's just the social anxiety blowing things out proportion. Nobody's perfect, everyone says things they regret. Take a step back, relax, and see if you can do better next time.