My favorites are the Bravado nursing bras, I have 3 or 4 in different styles and they are all great. You can check bravado.com to find a retailer in your area or do what I do and order online from breakoutbras.com.
I am a 36H so I understand the need for support, and the Bravado bras do the job. I also have a Freya nursing bra that I really like. You may want to check your size again, especially if you haven't recently, as the wrong sized bra is never going to be as supportive as one that fits correctly. The website I mentioned has great instructions for measuring yourself. I discovered I was wearing the wrong size and getting the right one has made a HUGE difference for me.
Good luck!