this is due to my sh!te piloting technique and "rustiness"
I commend your honesty. I find the Airbus quite easy to fly on manual thrust, and I am no Chuck Yeager!
However, if you are getting "Pitch Pitch" callouts on final approach; that's your problem right there. You are destabilising the flight path, which will affect your speed. I suspect when you get that sorted, your manual thrust approaches will become much easier. If your flight path is correct, the thrust should not need to be adjusted that much, except on very turbulent days.
Obviously, I'm guessing, (and I'm not a trainer), but maybe your instrument scan, or your glideslope tracking strategy need a bit of work?
Good luck!
U