The best piece of advice I can give you is to keep trying and be patient. I remember posting the EXACT same thing when Tyler started solids once upon a time. He turned his nose up at everything for about 1 month, then suddenly one day, he just got it. It was like a light bulb went off, and he finally opened his mouth. He was a little over 7 mo then, and I really thought I'd just have to nurse him forever. So your little man will come around when he's ready!
Also, keep in mind that it can take many exposures (like 10-15 or more) to new food before a baby will even THINK about opening up. Some just take more time than others!