I took the advice from many and talked to a lawyer this morning. He tells me there is no way in hell I'm going to jail for this. And so my heart rate has dropped to something that might be considered normal
As far as I know, the incident is still in the investigation-stage and I haven't been charged with anything, which is good. Knowing how the police here work, being undermanned and underpaid, an investigation could take months and I'm still going to be a bit nervous until I get the final word that no charges will be brought against me. If anyone should go to jail for this, it's the guys who tried to rob me.
Edit : Yeah, I'm a bit worried that they might try to get back at me, especially if they are in one of the two major gangs in Oslo. However, I refuse to spend my time being afraid of someone and what they might try to do. Guns are not as easy to come by in this country as they are elsewhere, so an attack will most likely come in the form of a knife or similar. I think I'm as prepaired as I can be for something like that. It's "easier" to handle a knife at point blank than a gun, 20 meteres away. Not that there's anything easy about being attacked, with any form of weapon. It's out the question to start carrying a weapon myself though