9mm and .38 Sp. are close
Jelly,
I view the .38 Sp and 9mm as very close in ballistics. Admittedly the 9mm is a tad more desireable as a self defense cartridge. They're both about the same diameter.
If you feel more comfortable and confidant shooting the .38 Sp as your defense caliber, consider a +P load(If your CCW gun'll take it) and practice and then practice some more. You'll have the advantage over most any common criminal if things ever turn violent.
I respect Jeff Cooper and Chuck Taylor for thier knowledge and experience, but I will never be as comfortable nor as confidant with a 1911 in the .45 ACP caliber as I am with the .38 Sp or 9mm. Good luck!
Respectfully,
Larry C.