I am waiting to find out but somewhere in the region of 1300?

Hi. I have been claiming carers allowance as I was caring for my son. I started working in September. I phoned the office to report my change in circumstances and realised that I had reported the incorrect start date. I have phoned again and reported this and then written a letter and an email to state my error which occurred because I was not paying attention to what I was doing as I am currently swamped with taking care of Children/ house/full time employment and studying. The lady on the phone this morning just said that there would be an overpayment and it would take around 3-4 weeks for them to contact me regarding this. She did say that they knew my correct start date for work because it flagged up on my NI number. Anyway I am going out of my mind since this with worry. Obviously I am happy to pay back the overpayment but I am terrified that my stupid error could cause them to think I was acting fraudlently. Have been going out of my mind and feel sick constantly and cannot sleep since I realised I made this mistake.