I can not be more impressed by how much effort you’ve put into this! Personally I had lots of trouble with my TOEFL exams before my undergraduate degree. One big issue I had was to pronounce my words correctly when I tried to convey something efficiently. I solved this by watching KZbin videos and repeat what the video says. This really helped me in terms of my speaking ability. I hope giving this small advice won’t be impolite! ちなみに日本人ではないですが、日本語は少しなら知っています!もしも返信してしてくれましたら日本語でも全然おっkです!