The default answer to this is to do a ton of right-pec drills, the point being to get yourself used to pulling close to your body at the right pec. I have a sheet hung in my garage for this stuff because I'm too lazy to chase discs if I'm not doing something directly relating to flight path/distance. Really learn to throw putters and things that need a clean snap to get distance, and work from your hit back, as the mantra goes. I benefited from slowing myself waaaay down for a long time. I played my rounds for about a month throwing just standstill throws from my left pec through my right one for all my shots, and it got me use to the snap from that position rather than from the downward angle you are using. So basically, snap from a standing position, then work on a pullback, then add more footwork/speed. Right now it will only mess with your timing.