Sudden loss of control

recently during a scrimmage, i did something really concerning - walking 3 batters in a row, and throwing only two balls for strikes before getting pulled from the game. my velocity was decent, hitting the 80s range, but it seemed like i hit everything but the strike zone. i havent been in this kind of situation since the first days of picking up a baseball years and years and years ago, and last season i walked about one batter every three or so innings.
after talking to my catcher for a while, he asked me why i was pitching sidearm. i found this confusing because naturally im an overhand pitcher, but eventually i theorized the side-arm delivery was probably due to the tendency to throw side-arm while fielding at shortstop (my secondary position)
im starting to get a little concerned - if my arm slot changes unconsciously during a regular season game, my walk rate might spike alot higher…any tips or ideas?

the armslot you pick to play catch is the one you should use when pitching. anything else will need tons and tons of practice to get it on every pitch.

At times we don’t have the same mechanics on the mound as we do otherwise. We need to be able to make adjustments quickly while in the game and honestly this is some of the things your coach and you catcher should be watching out for, hopefully they are in a position that you will take those recomendations and make the adjustments. You might need to ask at a some point “hey do you see anything different”. If he does see something then you need to make an adjustment quickly!

In this case, get right back to a bullpen quickly, get it out of your mind and get it out of your body now. I wouldn’t put too much too it, it is easier to make the adjustments there and you will be right back on track.

You know, I’ve seen this happen from time to time in the major leagues (my own area of expertise). A pitcher will go great guns for four innings, and then suddenly in the fifth he can’t find the plate to save himself. Or a reliever will come into the game, and his control just isn’t there—the curveball hangs, the slider is flat, everything is high. The odd part of it is, more often than not the batters just can’t do anything with it, and they swing and miss or pop up or hit line drives right at the second baseman. This is usually temporary—I’ve seen a pitcher just go haywire for one inning or so and then in the next inning everything just snaps back into place, his control is back, and he goes on with no further problems. And usually it’s the catcher who notices this and comes out to the mound to talk to him and get him back on track.
I remember Vic Raschi, one of the Yankees’ Big Three rotation of the late 40s to the mid-50s. He was a real power pitcher—and it’s often the case with this type of pitcher that his stuff will get away from him. When this would happen Yogi Berra would come out to the mound—only to be greeted with a surly “Give me the goddamned ball and get the hell out of here”: Yogi took this as a good sign, because it meant that Raschi was back on the beam.
So my advice would be this: when you run into this kind of trouble, call time. Step off the rubber and go to the rosin bag and futz with it for a minute or so. And call your catcher out to the mound; if he has any smarts at all about these things he can set you straight. Then get back on the mound, and try this—instead of throwing harder, ease up, go to your breaking stuff. If you have a backup pitch, such as a knuckle-curve or a good changeup, use it. This will take the pressure off, and most likely the next inning will find that you’ve got your control back. 8)