Are there any Grammatical errors in my letter?

Dear Sir / Madam,

Requests for the VISA to continue / complete study in ACT

I, Ivan Leonard was studying in ACT in Christchurch since Feb 2005 to Dec 2006 (2 years) doing Bachelor of Information and Communication Technologies (BICT). During the course of study I've learnt modern technologies some which I already know some which are really new to me. During the first year of study I found my self in a comfortable position and my grades were in higher level. I believe, due to the structure of the BICT in which each year consider as a level and each level structured be more advanced than the previous the second portion of the course got harder than the first level. In my intuition I was aware of the fact that in general in a reputable course, as a measurement for the course and the measurement for the student the course should get advanced in each stage. However...I believe that for a measurement for my knowledge I found the second year of the course was going beyond my capabilities which is evident when I received my result sheet of the exam that I have sat in which for most subjects that I've failed. At end of the level I've failed 6+ papers which include a combination of business and computing.
I've talked to my course coordinator regarding the future of my selected course and he suggested downgrading it to the Diploma level (i.e. Dip ICT) where I would best suite or to continue with BICT with another additional 18 months expecting to have more failures. During the preparation of my enrolments and VISA renewals my father caught up with a disease and hospitalized. This was shocking news to me since I don't know what was happening to my father in Brazil while I’m in New Zealand. I was expecting him to get cured since it was NOT considered as life threatening. But when the days passed he illness got worst and the he got diagnosed with disease knows as which was taking lives of so many, specially the ones in their senior age. Due to this unfortunate event my father couldn’t the send funds thus I couldn’t complete my enrollments and VISA formalities.
Then I realized that the best option is to leave New Zealand and return to continue the studies after when my father has recovered. Then I start to look for air line ticket to be booked. According to the travel agent the mid march which happened to be one of the busiest times of the year due to the coming ester where most of the air lines were booked and they were unable to book an Air Line for me to go to Brazil before my VISA expires. According to them, the earliest day that they could book an Air Line would be on the 10th of April on which I left New Zealand. I was fully aware of the fact that over staying is against the Immigration Law and I haven’t had any intentions of doing it. Unfortunately the travel agent couldn't book a flight for me to leave New Zealand before VISA expires therefore I had to adjust to their schedule without any options.

Due to the unfortunate and unavoidable incidents which I haven’t had any controller over I had to overstay for 10 days (from 1st of April to 9th of April) which I haven't had any intentions of doing. Therefore considering unavoidable human mistakes, please consider to issue me a student VISA thus I could continue my studies in ACT to meet my academic credentials.

Sincerely,
Ivan Leonard