You had a good 1911...and you dumped it for a Glock. That is all sorts of wrong.
But whatever floats your boat.
9mm is easy to reload. A simple Lee loader kit should cost around $20. Long term you'll save quite a bit of money and or learn to develop a load that your gun shoots the best.
6" at 18yds is ok. It doesn't put you in the top ranks of shooters though.
I'd suggest that competition shooting for a way to improve your shooting in the shortest amount of time.
Further if you can find a shooting team instead of individual, you will get all sorts of coaching free from your team mates.