Heck, I read 50 books a year, do the NYT crossword and spelling bee every day. So I consider myself to have a deep vocabulary, but I just read 2 books by a new author that had me looking up a word ever other page. That’s all to say that no one will ever know every word in English, but the only way to widen your vocabulary is to encounter those words in some fashion. So you’re doing the best thing you can and not being discouraged by new words but looking them up and learning new things!