I think the first thing I would have done would be to start the engine. It is easier to keep the engine running, even if the boat fills with water than to try to start it after its water logged. The engine can power any kind of pumping mechanism. If the water was coming in fast, I might be inclined to pull the intake on the engine water pump and let that help pump the water out. Secondly with the engine running, you have a better chance of controlling the heel of the boat. You might be forced to run around in circles, to help the boat lean, but that is what is going to keep the water out. Very early on, I would have also hit my emergency beacon. Worst case, if the boat sinks, the container seems to be floating just fine. On the way up out of the cabin, I'd have grabbed my life jacket, as who knows how fast the boat is going to go down. I'd have also fished out my inflatable dingy.
There seemed to be a mental disconnect in reacting to the fact that it was an emergency, as opposed to being completely distracted by the immediate problem at hand. When an emergency occurs, there should be a list of automatic things you do first, before you address the actual emergency. While I was taught that as part of my sailing lessons, the concept of preparedness hit home much stronger with my previous boat. It sailed poorly and was very tender. I learned to put my resources close at hand before I left the dock. Made sure I have everything I could possibly need, if something bad happened.