My English is far worse than yours in terms of grammar, I never managed to learn it so well, but I had always the knack for words. Somehow I remember them and thus I build up my vocabulary all the time.
I observed that the simple thing that helps me is to repeat the new word out loud whenever I can for the rest of the day. I don't care about actually remembering it, mind you, I may not even recall it if I'd want to use it in a sentence, but I remember it when I see it.
In addition, surrounding myself with the foreign language helps greatly. If I play video game, the language is switched to the one foreign to me. If I watch a movie, I skip the dubbed version, etc, etc.
I hope it helps.