Just you wait buddy. Pretty soon, we'll have you decked out in all the finery.
When it comes to appendix carry - counterintuitively 'bigger is better' for concealment purposes. There is a fine line between having enough gun below the waistband into the inguinal crease that the muzzle portion of the holster can lever the gun in more tightly and that a wing/claw/junk pad can help twist the grip up and around; and having a small enough grip that you can conceal it. I've found that longer barreled guns conceal easier in AIWB holsters.
You might also need to change your pants or pants sizing and/or the stiffness of your belt and/or the tightness of your belt. The recommendation of, "Size your pants up a size for IWB carry." does not apply to AIWB. In addition the recommendation of, "Buy the stiffest belt you can buy." may also not apply (mileage varies).
Jeans, men's jeans in particular, are cut roomier in front of the hips than in the back (that might be for uhh...'obvious' reasons). As a result you may find that sizing down your jeans means you can wear your gun more easily and more comfortably with less bulging. The reason being that wearing loose pants/jeans means you're cinching the belt tighter, causing the holster to twist (particularly near the belt buckle). Which compounds your problems. You can experiment simply by putting the gun on and cinching your belt tighter and looser and watch how the holster twists in relation to this.
Belt stiffness can often be reduced with AIWB carry, because the gun is supported by the hip/crotch (literally) and less on the waistband. Reducing belt stiffness allows you to have more flexibility such that the holster moves with your body as opposed to staying rigidly in place.
Since you have a mid-size Glock already, I suggest you run, not walk, over and pick up either a JM Custom Kydex or a Dark Star Gear holster for it. And then try on every pair of pants and shorts you have until you figure out what size of pants works best along with adjusting and readjusting the tension of your belt.
___
Personally, I've found only two IWB positions work for me as a person. AIWB and 3:30 just past the peak of my hip. And in both cases, they really work best for me with longer barreled guns (because I have a flat ass, I need more barrel length to lever the gun butt in for better concealment).