Chinese is not spoken in that way. So a direct translation - "我的中文不如我希望的那么好" - is very awkward, though it may be loved by advocates of 洋派现代汉语.
A more natural and Chinese way of expressing these sentiments is "我中文不好,希望可以提升。"
A good piece of advice to you is to learn Chinese without using English at all. Go to a Chinese teacher, use a Chinese textbook, and forget about English while you are learning or practising. That's the way that the Alliance Francaise teaches French anywhere in the world - completely in French from the first minute, never ever using another language. That's the most effective way of learning a language.