Hang in there. You'll be alright. I had a hell of a time with my injectors as well. Shyyt, took me like 2 weeks to get those gaskets done. Meticulous cleaning took the most time.
You probably have a tear in the O-ring. Had the same problem. I literally has gasoline boiling on top of the manifold. Take the rail off and check the O-ring for that injector. You probably know that much tho. Make sure you lube the O-rings in motor oil for added lubrication. When pushing the injector into the rail, or into the bosses, push it for a little bit and then let off for like 1-2 seconds, this lets the O-ring adjust a little to its new forced, slimmer shape. Push hard again, and let off for a second of two again...
Another trick to use, if the O-ring keeps ripping, is to heat the rail with a hair dryer, expanding it, and placing the injectors with lubed O-rings into the freezer/fridge to contract them, and then going at it. Good Luck!
