I always feel a little embarrassed when I get caught bluffing. And it is weird since bluffing is part of the corner stone of poker.
I think this is one of the greatest challenges with bluffing and with being a great player.
From a survival instinct, lying and stealing go against our human nature. If in history we were caught lying or stealing we would likely be kicked out of the tribe which would lead to likely death in the wilderness without the support of our family.
While we as humans evolve and technology evolve, a lot of these instinctual things from millenia past are still in our DNA. I think this is where the bluffing dilemma comes into play.
When we are 'caught' bluffing (even the word caught has an implication that we were doing something we shouldn't have been doing) the other players will see that we were trying to 'steal' the pot and that's a big no-no just about everywhere except for the poker table. And I think this is where the feeling of embarrassment or shame creeps in when our bluff doesn't get through. It's just a natural instinct to not want to do dishonest things, much less be caught publicly doing them.
The task therefore is to recondition your mind so that it understands when you are playing poker, you are playing a game, and the game is about winning by playing well. And that the actions you take on the poker table need not reflect ones you'll take off the table.
When we can reaffirm in our mind that people won't judge us off the table by how we play on the table it can sort of override this hesitation and fear of getting caught. This also bring the nervous levels down when going for a bluff, because both the fear of being caught is lessened and the fear of losing money are lessened (because we've told the mind that we're just playing a game and that in the game winning and losing is ok).
That's another fear of bluffing, we as humans are not programmed to enjoy losing or wasting money... man... so much psychology that carries over into poker, I love it!
Anyway, this is where using pre-game meditations to connect with your subconscious mind can be very helpful and turn off the natural programs that keep you from executing on the plays that can make you money in the long run.
Hope that helps! & Here's a little video on the optimal way to bluff vs different opponents