When we start learning a language as adults, we can't suddenly become "native-speakers", but reaching native-like fluency is an absolutely realistic task.

You already have a great advantage - you speak another language. 

When you can communicate your ideas clearly both in writing and in spoken language, when you can sell, provide great service, hear what your customers really mean (every word of it), and read between the lines in your first language AND in English - you enter a different league of cross-cultural communicators. 

I know you belong to a different league. My job is to give you the training you need to play in the big leagues.