I suck at building pots, making money and poker in general

In order to win a big pot, you have to build a big pot. That means betting. You have to bet that flop, even if small. Bet the flop, then the turn, then the river. That's how you build a pot. Somebody with the nut flush draw will probably call, and you'll often get two pair too. Sure plenty of times everyone will fold, but the times that you win a massive pot will make it worth it. You have to give them a chance to put some money in that pot. Checking the flop and check calling the turn is not accomplishing building the pot. And when you do do that, you then have to over bet the river in order to get some real money in the pot. Bet the flop, bet the turn, and then bet the river.

Edit: I also would add that flopping a straight flush is no different than flopping a set on an harmless board. Your winning percentage is still huge and you need to think about maximum value. Flopping the absolute nuts means nothing. If everyone folds the flop so be it, but you have to get value out of this hand when someone actually has somethng. Furthermore, betting out gives no one any clue as to how strong you are. They might actually play back at you representing the nuts. Play the straight flush the same way you would a set on a draw free board. Bet!