My (forum) name is Straightpool_99 and I'm a banger. I had a similar experience to yours trying to beat the 10 ball ghost. I am now closer to the goal, but I still need at least 3 games on the wire going to 10 to have any kind of chance. Remember that the ghost drill only measures your ability to run out. In my case the 10 ball break I used kept leaving 3 -or-more ball clusters usually with the lowest balls in it, and I had to adjust to better my scores. I beat the 9 ball ghost at this time, but I got stuck immidiately playing the 10 ball ghost. At the first attempt the Dr. Dave test had me rated as a D-player

, all because of my poor break and also bad luck.
In all seriousness I think you are a bit hard on yourself. I assume you can beat the 5-ball ghost on the same table? If so, it is reasonable to assume that you are either not breaking well, or you play to loose of a game position-vise. The break is more easily fixed, so work on that for a day or two and see if you improve your score. If it doesn't then you know what to work on. I think the 6-ball ghost (on a reasonably tight 9 footer) is maybe the single most important plateau in most players game, and is where most semi-serious poolhall regulars break down. Once you get past this point and can beat the 6-ball ghost reliably, you are approaching a level of play that 80% of people playing will never reach (ok, you got me I made that number up). IMHO if you are capable of beating the 6 ball ghost you likely have all the tools needed to beat the 9 ball ghost. I skipped directly from 6 to 9 balls and the transition was not a big one, and nothing like going from 5 to 6.
I find that playing the ghost I tend to do better playing "insurance position", meaning taking a bit longer of a shot when I have to,in order to insure getting a shot and being on the CORRECT SIDE OF THE BALL, whereas playing regular pool I try to get a bit closer. Bert Kinister has videos called "The Short game, The Medium game and The Long Game which are excellent drills to work on this aspect of the game. Worth a watch. They are on youtube, but don't be a cheapskate, pay the man for a subscription. If you can look past his excentricities his stuff is amongst the best available for position play.
A last word of advice (I'm no stellar player so take it with a grain of salt): Learn to bank well. It may be the most neglected area in all of pool development. If you can bank really well you will run out games that your opponent won't, and it is extremely important playing the ghost, especially when balls tie up near rails etc. Not to mention that you can shoot your way out of your mistakes many times.