Could you pls correct my wrong grammar...

Although the term of serving military has been cut down to eleven months, and the days wear on like years beyond my expectation. As a Corporal, I could feel a totally different kind of system operating. From a solider as a learner to become a corporal as a leader, I’d learned to use multi-intellectual to get along well with different types of people; also, I needed to complete the missions which were given by the chiefs, I was glad that I had handled them very well. I’d been thinking over again and again for my future direction, my body and my mind also had been tested under this rough circumstance. After finishing serving in the military, I could be perfectly calm to deal with any challenges due to such a suffering environment.
While serving the military, I had experienced the epitome of real life. The limitation of education background and the requirements of working experiences in all respects encouraged me to continue studying graduate school. Finally, I was enrolled by Institute of Applied Arts xxx University, and this is what I have been studying now.
When I’m in graduate school, I’ve taken several courses that are related to industrial design which improved my weakest skills; I’ve taken other different kinds of classes as well such as visual design and architectural design. By participating in different academic fields of studies, I’ve understood more about design and feel more substantial. I believe that I’m inspired to create various novelties in virtue of different kinds of students who are from different fields of studies in graduate school; moreover, getting along with classmates is one of the methods to learn. I realized the importance of the interaction among different fields of studies by using the most effective solution and professional knowledge to solve the problems successfully with the help of the classmates who were expert in filming in the design of product class of my first year. Furthermore, I won a gold medal award in Great design Competition. The teachers see my devotion to design; I had once cooperated with my teachers to design an auto machine that can return books and lend books to people by itself during the summer vacation; thereafter, I will assist my teachers from visual design department in displaying products in foreign countries.
I truly realized that only so we accumulate abundant life experiences and new things that we can advance our knowledge, because of this reason, it enhances my motivation of applying for exchange student program. I hope to broaden my horizons and become a muti-thinking person.
Thank you for reading my autobiography!
ps. I'm currently studying in graduate school and I already finished serving military. Which tense I should change? and how would a native speaker say. Thank you very much!