what sort of explanations should i give to the Home Office would be the best ?

I am an international student from China. I have accepted the MsC banking offer Queen Mary as well as meeting the entry requirement.I have studied in Nottingham Trent University for the last continuous three years. I have a problem regarding renew Visa. Last year's September,i forgot to report to the police station that I have changed my address. Basically, i just changed my flat from 10A to 79D. I have reported to the Nottinghamshire police station today, and they inform me that the Home Office is likely to refuse my new Visa application or make the application fee higher. I really don not know what i am supposed to do? I had no bad intentions not inform the police station ,i just forgot that and i was too absorbed with the final year studies. My parents will be utterly disappointed and angry with me if i cannot further my study in Queen Mary just because a mistake which i could avoid. The Queen Mary says that this should not have any problems, but they recommend me to offer a letter to explain why I registered your change of address late. Could i just say i was too absorbed with the final year courseworks? And put all minds and efforts on it. SO , i forgot the important matters like registering with police about changing flat from 10A to 79D?????? Would this be enough to please the Home Office not to reject my Visa or enhance the visa fees? I swear I will not forget again. I have no intention to immigrant to the UK although i do enjoy living here. I also have no desire to find occupations in the UK either. :confused: