Angelina
My recommendation.:
Read plenty of English books, watch English news channels and movies and ask Camryn to talk with you in English, not trying to simplify her language. That way your English (vocabulary as well as grammar) will greatly improve.
In today's business world a perfect command of the English language to a level where you can even handle the most delicate contractual negotiations and understand subtle differences is a great asset to have. With a native speaker as partner you have the chance to getting there without actually having to live in an English speaking country. Most Germans will never reach that level.