I've been there - it's so stressful! My LO acted exactly like yours, and I dreaded feedings. It was so, so hard on both of us, and I knew that she wasn't getting enough. Rice cereal didn't work for us - it made her really painfully gassy and constipated.
After trying the rice, we started off on a low dose of Zantac, which seemed to help some for a couple of weeks. Then the reflux got really bad - worse than before the Zantac. The pedi upped the dose to the highest recommended for her weight, and now she's like a different baby. She eats peacefully, and we both actually enjoy feeding time.
Definitely ask your pedi about upping the dose or trying a different medication (we were going to try Prevacid if the higher Zantac dose didn't work). In the meantime, I know this goes counter to all reflux advice that says to burp frequently, but I found that LO did much better if we didn't stop to burp her midway through. Even now, I only burp her at the end of a bottle, unless she pulls herself off. That works much better for us, so you might want to give it a try!