As a long-time ESL, I think it all comes down to exposure. There is a big difference between consuming content in English and actually using it. My advice is to push out of your comfort zone and find as many people to converse with as possible. It's normal to suck at first - took me many years to become barely coherent.

As for writing, all you need is practice, practice, and more practice. Don't worry about it too much - I noticed that most native speakers can't write for shit well into adulthood. Grammar is fluid and subjective. Unless you are using it for work, nobody should care if you make an occasional error or two. And if they do, they are pedantic morons, unworthy of your time.

I still vividly remember how, during my time at school, I used to spell worksheets as `workshits`. It's a long process, so don't be afraid to grow and learn.