I had my bench up around 350 when I royally screwed my left shoulder. I still can't lift more than 135 without pain, just like you. The difference is that my problems started with a nice popping feeling in my shoulder. Not good feeling. My pain is in my front delt, but I've been told that it's a rotator cuff issue, which is exaclty what you might be having.
I agree with the others that we may be able to help you with form. That could very well be the issue. Also, I'd suggest looking into movements to strengthen the rotator cuffs. I do much more warming up now before I do any pressing movements to make sure the entire shoulder girdle is prepared for the loads.
As far as benching, unfortunately I've had to give it up for now. I'm taking the opportunity to focus on my shoulders which have always been a weakness for me. The standing military press has become my best friend!
Current PRs at 242- 495, 345, 585, 1425