F. Damn, that was unfortunate my dude. I hope you're doing well from here on out.
Truth be told I actually almost had the same fate as you. Just 6 hours ago I was replacing my LPG tank because I realized the one in use is empty. When I'm placing the regulator on it and was about to lock it I realized that it wasn't sealed correctly. So I tried to remove the regulator and suddenly the gas is bursting out of the tank filling the kitchen with it. And so just like any other normal person would do I was startled by it and unable to think what to do for a good moment. Good thing I wasn't alone at the moment and their panic-induced voice somehow pulled me back to reality. We decided to bring the tank outside so the gas wouldn't fill a room and covering it with a wet cloth so the gas wouldn't spread as badly. Not knowing what to do, we called for the fire department and let the pros handle it. For a good half hour(which felt like forever), we just sat there soaking it with more water whilst waiting for them. After they arrived with I assumed is their full force(it's a small department), they asked for the detail of the situation and did some inspection. It seems that the cause of the leak is from a faulty sealing pin, so they used a lengthy tiny wooden stick to poke the pin to fix it. And so after some chats and advice, we went on with our lives. All in all disaster was averted and I'm grateful that the only loss we had is the $12-ish LPG tank and nothing more.