Why do I have such a struggle with English? How can I improve?

Because you are trying to look at everything logically in English. English is not science or math. Think about it, in math 2+2 IS 4, it's set in stone. But in english, the sentence 'I went to sleep,' can mean many different things to other people. English isn't about using logic at all like science and math. Do you get where I'm going with this?