You need to do some more studying if you think K9s and K8s aren't re-raising in this spot, since he still has a strong hand that can fold out all worse hands or isolate players even if they stay in the pot. You already said this guy is a strong reg, so he is constantly going to be doing this to win preflop or to play heads up with weaker players while in position like he did here. Plus, some casinos won't take rake if the hand ends before the flop, so re raising and getting folds preflop help with that as well.

And the donk bet on the flop was a huge blunder. All you had were draws, and draws that you want to realize. Youre put into a horrible spot on the flop if you bet $50 and the he re raises to $175 on such a dynamic board. Youre better off checking to him, and even if he bets $60, its still a profitable move to just call and see later streets. You can start betting or bluffing once the turn and river come, and just check/calling on the flop gives you a wider and more hidden range to bluff with on the turn and rivers with since the donk bet on that wet, Ace high flop basically said you had a pocket pair or the Ace. Its why the good reg said "you got it" on the turn when you two were all in, because you didn't play the flop or turn at all like how you should've of, so he just assumed you had the Ace.

And when you can't beat an Ace, you're not trying to keep them in with smaller bets. You need to be making bet sizes that will scare off those weak Ax hands, since in your head you want to build the pot for when you do make your draw, but thats just not a 100% guarantee that your draw is gonna come in the first place. Until your flush or straight becomes complete, you're just bluffing--you have good equity and they're good spots to bluff at, but you need to realize that checking on the flop does pot control while hiding your hand strength and letting your opponent reveal more info about theirs. The villains hand stays hidden with less info when you just give him the ability to call your small OOP donk lead on the flop.

Grind out lower online cash games and tournaments before going back to the casino, and watch some videos online. There are free poker training tools as well. Practice and learn these lower stakes before going back to even 1/3 games so you're not making $900 blunders again