While we're waiting for Hal, google a mix these search words: san diego, pitching, coach, instructor, instruction, softball, fastpitch
Finding a good one is tough. They are out there, but in my area, I might only be able to recommend 1 out of 10. I'd bet you'll get a good lead from someone here in a bit.
Three things:
-Go to a farm supply or decent hardware store and buy a 4 foot x 6 inch strip of 3/8 inch stall/shop mat. Cut it in half and you have two pitching rubbers. Get a roll of "no residue" duct tape and it only takes 3-4 six inch strips to secure it to a carpet, floor or driveway. (If I had a choice of surfaces in preferred order, I'd pick dirt, grass, carpet, a smooth floor, then concrete only if no other option was available.)
-Work on leading the downswing with a flexed elbow and pausing at the side during the whip.
-Work on a more explosive drive, but at the same time, eliminate the walk through after release.
One more: wear athletic shoes if cleats aren't appropriate.
Ken