hand 1: he has top pair and the nut flush draw. he reraised because his hand is massacring your hand. in addition, there's no reason for him to put you on a good hand because you didn't raise preflop. Your river "bluff" was 14 into a 35 pot, showing the strength of a 4 year old girl, his call wasn't bad.

Hand 2: bluffing doesn't involve minraising, or making less than half pot sized bets. he was right to call down these bets. bluffing is intended to scare your opponents away with how much you're willing to bet, not make tiny reasonable bets that are easy to call with a tpgk hand.

hand 3: fold the flop.