You can try 家計會, or private doctor to refer to hospital. As far as I know, Prince Wales, Kwong Wah and Queen Mary has centre for it. But the queue is long. You must choose one hospital near your home as you need to go back to hospital quite often.
If you can afford the cost, you can ask the hospital for private consultation (私家). The queue is short. The cost will depend on your condition. It's difficult to tell.
I recommend you go straight to refer to hospital. Don't waste time at 家計會.