dude...I have fixed 100 softball pitchers...you have a case of Steve Blass Disease...I got it once too...sucks.
two things
...you may actually have done something to the nerves in your arm which change the feedback you are used to getting...so you are throwing untethered. If you've had trauma to your arm or shoulder, or tendonitus, it can goof you up because the muscles don't fire right, and provide the feedback you are used to. Go get someone to do a dry needle procedure on you (physical therapists do it), shoulder, elbow, and wrist. Then follow the physical therapists instructions...
...you may have talked yourself into reliance upon feedback that is a liar...get on the mound with a bucket of balls, put a catcher behind the plate, and a video camera next to you and start filming. Look at the target, and close your eyes, go through your routine, and deliver the ball. keep your eyes closed until you hear the ball hit the glove or dirt. Don't ask where the ball went, and don't focus on that. Keep doing it. If after a bucket, your catcher says you generally throw strikes, you need to keep doing this in your warmup routine because you have lying eyes...which means your mechanics are fine, you have a tendency to lose them based on trying to compensate for bad feedback from your eyes...you need to drive muscle memory, and confidence from feel, and use your eyes only pre-pitch, and then become a robot. If you are off and all over the place with mechanics ( you'll know when your catcher tells you and after you review the film...its feedback other than eyes...see my first suggestion...
Also, if you have significantly changed your load, or your workout regimen, that can screw you up. DO the blind work...it will all come back...just don't freak out. Your brain is the enemy to mechanics...
