The horizontal spread is probably the result of grip variations, possibly thumb & finger tip pressure. The shots out in the white are most likely anticipation, which can come from forcing the shots off. You need to concentrate on increasing the pressure on the trigger smoothly. As long as you do that, the shot WILL go off, but you won't know exactly when. You don't have to do it super slow. Practice dry firing and work on seeing how quickly you can squeeze the trigger without disturbing your sight alignment. Most shooters take WAY too long to get their shots off.
https://www.targettalk.org/viewtopic.ph ... 11#p314411
In my experience, a backwards pellet usually shoots just fine in most pistols, but the hole in the paper does look suspicious.
It actually looks like the center of your pattern is low, and a sight adjustment is needed. The scattered shots above that may be from losing focus on your front sight. It's important to "call" every shot. If you didn't call your shots accurately, you are probably not concentrating on sight alignment and your focus is wandering.
When you get a good shot, try to think about EVERY detail that went into that result. That will help to make them happen more often, and if something is not right, it will help you identify it BEFORE you take the bad shot.
When you get a bad shot, think about what might have caused it, and what corrective change would have prevented it. Then forget about the shot, and work on your technique. Think in terms of POSITIVE actions, like focusing on your front sight and smoothly increasing your trigger pressure.