[Unguarded]

Ok, first of all:
1) You are very rarely against a flush draw. Pound away on the river if a flush card falls. The only time you are in anything resembling trouble in this hand is when someone holds AQs with a flush draw... even then you would be trying to get more money in the pot from the third guy. Don't even think about this bizarre possibility unless things get crazy on the river.
2) I ran a "disaster scenario" through PokerStove. This stuff should be second nature, but hopefully this helps illustrate just how well you are doing here. One villain holds TT and the other holds AQs with a flush draw. Your equity is still 30%! In other words, capping the turn is still absolutely fine. If one villain holds AdKd, and the other holds TT, your equity is almost 60%! When one villain has a set, and the other has 2 pair or a set, your equity is 80%! When both villains hold 2 pair, your equity is between 88 and 95%!
3) Your post clearly indicates that you could benefit tremendously from studying the game a lot more. Books, posting here, thinking about hands you played, etc.

Ok, now to your actual line in the hand. Pre-flop/flop are obviously fine.

Turn: Your plan to C/R the field is good, but calling the bet-raise is absurd. 3-bet, expecting 2 calls most of the the time, and a possible cap. If UTG+1 folds, that is fine... you still may win a ton of bets on the river from CO.

River: If a flush card falls, never, ever fold. Lead the river, and 3-bet if given the chance. If it goes bet-raise-3-bet, then you can just call. If the board pairs, check the river and call one bet back to you. You can fold to check-bet-raise.

Edit: I should have mentioned why you are very rarely against a flush draw on the turn. When villains bet-raise here, it usually means both of their cards are already in use. One of them would need to specifically have AQs, Q9s, JcTc, or a king with 2 diamonds for it to make any sense for them to play this way with a flush draw.