Well, It didn't take long before I figured it out! The problem was my voice recognition module(TEMIC). When I was doing my troubleshooting I removed the TEMIC(picture on the left) to see if that was the problem, but I forgot to replace the SES jumper plug(picture on the right). After spending a whole week trying everything and doing a lot of online researches, I found this article:
BMW Bluetooth X5 retrofit - Bimmernav BMW Upgrades.
Everything is back to normal except, my voice function is disable. I ordered another TEMIC from eBay.