The answer depends on your own perception. For me, because I like learning English, I don't think that this international language is difficult. Yes, there were times when I got confused with grammar, vocabularies and pronunciation. That's some of the challenges that I faced during my early years in learning English. I still make grammatical mistakes therefore, I keep on studying English.
If you feel that English is difficult to master, you need to share the burden with other English learners. They will encourage you to keep on moving ahead and become successful English speaker. Today the number of people who use English as Second and Foreign language is higher than the native speakers. Even in Asia, you can find countries such as Singapore and Malaysia where English is used in every aspects of the citizens life. It means English is not difficult. All we need in mastering this language is patience and persistence.
Besides learning grammar and memorizing vocabularies, we need to practice conversing in English. It is ideal to converse with native speakers but if we cannot find native speakers, we can simulate an English conversation environment in our own English club by practicing samples of conversation given in this website or other English learning software and recordings.
I believe that if you continue to improve your English, one day you will have more confident in using the language not only at work but also in every aspect of your daily life.