Improving English writing skills shall not happen in a day. It requires sustained efforts for years.
But once you master it, its yours. And people will appreciate you for that.
Don’t be impatient with yourself. All that you plan might seem to be falling off initially. But, push yourself hard to get over the starting phase. Things become easy thereafter.
Writing cannot be a standalone activity. Unless you read good quality books/journals/blogs, you are unlikely to develop good writing habits.
Don’t be let down by disparaging comments from people. In my case, such comments actually helped me in executing the long term plans.
Remember - “If people are not laughing at your dreams, then they are not big enough” (Grayson Marshall).