Normal
I graduated with a 59% overall (borderline 2:1 as classified by my uni) and got a TC at a top UK firm so don't lose hope at all. You also have final year to boost your average and that will be easier now you have learnt from mistakes in previous years. Some firms might pick out that grade and question you on it (I've had questions like this from firms such as Stephenson Harwood) but you have valid reasons to back it up. Maybe also focus on an answer of how to improve from this too to show you're making active efforts to improve