Well I'm not really sure what AA ball is, but I'm sure you'll be facing some big dudes who know how to hit the ball. Alot of people think that suddenly because the hitters get better, they are going to have to throw like 50% offspeed, and that any fastballs are just going to get killed. While I dont deny the fact that that to some of these hitters, an 85 mph fastball middle away isn't going to do much like it did in Highschool, you need to remember that your fastball is the pitch you build everything off of. Locate it, keep it away and below the belt to that 6'2 200 pound lefty pull hitter. When you leave one in, and a guy yanks it a mile foul, well, dont leave it in again. But don't suddenly think that because you are playing at a higher level that your fastball is now useless.
But on the other hand, your offspeed arsenal is going to be at the forefront of your toolbox now more then ever. Some things that I've found effective when pitching against D1 or D2 recruits home for the summer are-
Start righty's with curveballs, but try and make it a perfect pitch low and away, or have it miss. If you do miss, then double up on it the next pitch. They guy will be sitting dead red, and you could hang one down the middle, chances are you'll still get away with it.
Double up, even triple up on changeups. All the way through highschool, guys teach themselves that if they miss a changeup, 90% of the time a fastball up in the zone is coming next. Throw them another one and watch them take the same bad cut a second time. Now hes in a position where he realizes the change may be coming a third time, but instinct is telling him to sit fastball. Any pitch will work here, a third changeup can usually induce a weak infield grounder, fastballs located well will usually put him away, and a hard curve in the dirt can usually create an ugly looking cut.
Fastballs up and out of the zone don't work so well any more unless you have a strong fastball for that level. I prefer to use an 0-2 fastball off the plate away, it sets up your offspeed better, or another fastball in creates jamshot city.
The thing to really remember when you move up to a higher level, especially as a pitcher, is that you still have the upper hand. 2/3 times, you should beat the hitter, and thats if your a bad pitcher. The only difference is that mistake pitches get punished more, and once and a while a good pitch is going to turn into a good piece of hitting and leave you shaking your head and tipping your hat to the batter.
I am a similar pitcher to you btw I think, I throw throw at about 82-87 and sit at 84-85, with a good curve and change. If you struck out a ton of batters at highschool like I did (I averaged about 10.5 thru 7) your probably going to see that number go down. Its fine. I averaged only about 6 per 7 this summer, but my ERA dropped a run and a half, walks went down, and wins went up. Pitching at a level where you can't rely on being able to let three loose down the middle and get a K is important to any pitcher, it made me a hell of a better one.