Oh man, yes! The blank page is the real killer, not any of the rules people complain about. I go to a group in my town and we spend the first ten minutes just staring at our notebooks like the paper owes us money. What finally helped us was doing a quick warm up where everyone writes one bad sentence on purpose, and somehow that gets the words moving. It sounds silly but it works way better than waiting for some perfect idea to show up.
A buddy of mine had the same problem and started keeping a note on his phone full of terrible first lines, just so he would have something to steal from when his brain froze up. He said picking the worst one on purpose made it way easier to just start typing and fix it later. Doing that on purpose seems to take all the pressure off.