Yes, you're right...people offering help always makes it worse! If it's a stranger I'll just say "no, I'm fine" and try to get away someplace private. If it's a friend or loved one I try to tell them as gently as possible that I know they're trying to be helpful but I really need to left alone. I just need to get away from everybody and hang on till it's over. I can't imagine being able to cover it up, though.