[CasinoR7]

Check raising on the flop is good. A check raise here can either win the pot right now or build a nice pot with a strong hand. What do you think donk betting would have accomplished here? Your opponent would have folded a worse hand or played back at you with a better hand. That could only have led to winning a small pot or losing a big one. So I think that your aggression on the flop was solid play. I have noticed online that some loose aggressive players feel "pot commited" after a check raise.

Don't back off because you got called by a loose player. Depending on the board texture, your opponents hand range and the betting in previous rounds, TP2K can be strong and a made flush can be a weak hand. Don't think that on the scale of all possible pokerhands, top pair is weak. Read the board, three of a kind and two of kind are always possible, but in most situations you can't put your opponent on a hand that strong.

Consider the percentage of times your opponent will call you down with top pair/weak kicker or with medium pair and base your hand strength on that information. Against a loose opponent you should be happy to get the money in with this hand.