Alex, 3 big suggestions for you to improve your chess: Play more blitz, learn opening theory, and stay open-minded. I am not sure how much time you spent at the start of your games, but even up to move 16 in your IMSA game you were still in opening lines.
In round 3, you made it way too easy for black. In the accelerated dragon, the bishop on g7 doesn't become a big threat unless you let it. Playing Nxc6 and not blunting the long diagonal with a move like c3 allowed your opponent's bishop to function on the diagonal. Instead of Nxc6, you should have played c4 and continued on with development. This opening is the Accelerated Dragon/Maroczy Bind. You should look into it. Playing c4 makes it much tougher for black to achieve the d5 pawn break which opens up the position. The resulting position is very comfortable for white and you should have no problem winning.
Against IMSA you played very well until move 24. You have to make sure that you are getting counterplay against George's king. That is the only way you have a chance to win. You let it go and let George do all the attacking when you played 24... Rg7 and 26... Bf6. Instead of Rg7 right away, Gxf4+ would have been much better. If Kxf4, then you take the d4 pawn, and if gxf4 white's pawn structure is destroyed and now Rg7 would be much better because it occupies an open G-File. If white also tries to gain control of the G-file with his rooks, then exchange the rooks. This makes the position much more drawish. In move 26, you should play exf4. Yes, it does open up the e-file for white, but will be no use for white if you keep hammering white with threats on his king with moves such as h5 followed with f4, and eventually get your own kingside past pawns. White's idea of pushing his pawn to victory lane is seriously slowed down because of his weak king and your constant threats.
The Mt. Prospect game was covered by caughtupinthemoment.
On move 56 in round 6 g5! would have made it pretty difficult for him to play. If I'm not mistaken, he's just dead lost there. Round 3... Wtf are you doing. It felt like you have no idea what went on in the opening. Last round, it felt like you were dead lost even after Bxg5. His pawns are just too strong. Btw if you don't know george, he could be pretty intimidating since he doesn't use any time. Basically, just ignore his shit and just play chess. And yes, he is extremely cocky and arrogant.