Learning foreign languages is great, and it's never too late to start. A few months ago my English was also at a bad level, but I thought about it when I was offered a great option to study in the USA. I realized it was a chance not to be missed. Although I can't say with certainty that I can read Harry Potter in English, my level is improving and I'm satisfied. Plus, when writing essays and papers, I use best editing site essays to improve my grammar. And I wish you good luck in learning languages. You will do well!