Sorry to cause confusion, but I feel your pain. Reloading is rewarding, but it can be frustrating at times. I remember trying to find a minor load for .38 Special in a 4" gun to use in IDPA matches. Nothing I tried would reach the minimum velocity I needed.
Slow powders are what is used in the loads for maximum velocity per bullet weight. They burn slower and and for a longer time in long barrels. For instance, 2400, N110, etc. Fast powders are such as Bullseye that burn faster and are for lower velocity target loads where less recoil is wanted. Medium powders are, well, medium.
I noticed that your bullet has 2 crimp grooves. I'm guessing that they are to load to the same COL in both 38 Special and 357 magnum brass. If you are using 357 brass, then crimp in the groove nearest the bullet nose.
Just keep trying. It's a Long Way to the Top If You Wanna Rock N' Roll.