I started a new job in January and it's been so stressful and horrible. I've spent the last year utterly miserable and in tears most of the time. I nearly made a massive mistake yesterday crediting back the incorrect amount to a customer I deleted the credit from the system and my supervisor even checked to make sure it was deleted and agreed it was but I'm still driving myself crazy that something has gone wrong the credit has gone through and I have credited back an amount which could get me sacked. I feel like I'm going insane, I am so worried all the time about losing my job that I'm having panic attacks nearly everyday.