I fuckin' hate sympathy.
When I am in a bad mood, offering me a hug is quite possibly the best way to get me to kill you.
I dunno why, but when I am angry or hurt I get defensive to the point where even the most honorable intentions in cheering me up are seen as an all-out attack. I respond, usually, with a Glare of Death, by hissing at the person, or by growling something along the lines of "leave-me-alone" before trying to bite them if they come any closer.
I understand that you are trying to be nice.
I just don't like it.
I can deal with people insulting me or mocking me. I just cannot handle positive reactions to anything I do. Example: I respond to compliments as if I've been physically attacked (gotten better at that lately, but I regress a bit every now and then) - I curl up and try to hide. If someone mails me and says something nice about my art, I literally duck my head down towards my shoulders as if trying to make myself a smaller target. It's a reflex.