I made this joke with this girl (22) (who I thought was my friend, we've been speaking for 6 months) and she got annoyed/angry and blocked me on snapchat. She said, "We're not friends. I don't feel like joking around with you. You could've just asked how I was." I apologised and asked forgiveness. I said how it was a stupid joke and I was inconsiderate. She's depressed so I was just trying to make her laugh but it backfired. The joke was that I said how "You're famous now... someone uploaded a vid of your gameplay. I really enjoyed your kill compilation." She plays video games for context. It seems she got annoyed by the "someone uploaded vid of you" part, now that I look back it does sound sketchy but that wasn't my intention. We always used to make dry jokes like this in fact she made one similar to this a while ago. I'm trying to speak to her on this other app but she refuses to talk. I asked why did she have to block me right away without saying anything. She said there's no point in talking. Prior to this she unfriended me on snapchat 3 seperate occasions over little things. One of those things was when I needed to sleep and cut the convo early. She said this is the exact reason this isn't going anywhere and unfriended me. 
I messed up so bad can someone please help me recover from this. I'm really confused by this because I've seen guys say worse things to her, literally degrading things but a slight mishap with me she throws a fit. Should I give her some space? What do I even say to her... I already admit my mistake and apologised.