My new embarrassment is that I miss a great chance result of my English

I am a contractual  worker in a big campany, and responsibility for tape backup administrate.One day ,My colleague talks to me having a good chance for me to manage Change management, I am glad when hearding it .We talk with this exchange job for a long time ,but ,finally  she tells me it is difficulty for my new job with no other way.Exactly for my poor oral english ,because I have little time to exercising it ,now I am deeply embarrassment, I miss a chance which I have never meet again .Why not learn english well before .Who can tell me how to learn it well ?We need your help .waiting ....expecting...