Could you please improve my language (my sentences)?

The idea of a portfolio was a great tool to help me combine my work efficiently. My purpose of doing so is to show my ability of reflecting the feedback that my teacher gave for each writing the next writing I did. It was also to show my improvement in using a range, suitable and precise vocabulary and to improve my writing style. In fact, I was happy with my progress because I could achieve all of these aims and that helped me to reach finally the band 7. At the beginning of my writing, I was able to use a range of vocabulary and my writing style was also very good. Through more writing, I could to use more precise vocabulary and improve my writing style further. I would say that this “my writing style”, my high level of fluency and accuracy are my strengths as a writer. Indeed, I do not think that I had that many weaknesses to talk about. Yet, I feel that I still a little bit confused with using articles, though my teacher did not comment me on that point enough.