[how_can_losing?]

OP, I agree with the other posters. If you aren't willing to felt this hand with this flop, you should not raise with it preflop and you should not bet the flop. He obliged you with a checkraise, now push and make him dodge all your outs--twice.

I used to play the hand as you did, but mostly because I was uncomfortable with getting all my money in on a draw (i.e., not comfortable with the stakes). I'm not saying this is why you played as you did, but I sometimes see others playing combo draws passively against one opponent, and this is a sure way to lose money in the long run.