I feel for you there mate.
I said "excuse me" and nobody moved so I repeated it and moved forward and, yes, I pushed my way through.
My limit is two "Excuse me" requests. The second one in a loud voice just in case the people didn't hear me the first time. After that, I'm more than happy to barge through the crowd.
I did get to the bag but I pissed at least one person off in doing so because as I wheeled the bag back out he put his foot out to stop me.
If he can't see what you're so obviously trying to do and accommodate you, then too bad for him. I've extremely little patience for people like this.
I've never had the balls, but I've heard that a very loud "I'm about to be sick" can gain one valuable personal space.