Thanks for the responses everyone!
However, I just want to add that my research proposal was corrected by my old Japanese teacher at my language school and we reviewed it together many times before I submitted the final draft.
Honestly, in my opinion, there is no reason for my latest draft to be riddled with errors when I only added in a few new sentences because 90% of it, in its entirety (not individual sentences) was checked by 2 Japanese teachers. And considering that I was accepted into the school, the first draft could not have been that bad.
Finally, I don’t mean to come off as arrogant, but I have always been complemented on my writing skills, but I’ve never received so many corrections so it kind of hurt my ego a bit (I work as a professional translator to put things into perspective). My main goal was to practice speaking, so I wasn’t too worried about the writing component, but it took so long just to get through half of my document that I didn’t even have time for speaking practice during the lesson.