I don't believe in something called "putting feeling" into music.
Can you tell the difference between a human and a midi sequencer performing the same piece? Checkmate.
You are supposed to play what is on the score, but you're supposed to play more than what is on the score. Your job as a performer is to interpret the score and turn it into an emotionally compelling series of sounds. This expectation of interpretation isn't obvious to english speakers because 'performer' and 'interpreter' generally mean different things. But in other languages (I'm thinking Romantic languages specifically) 'performer' and 'interpreter' are in fact one word.
So, if an adjudicator has told you to "play with more feeling", what they're saying is that your performance sounded mechanical, perhaps technically correct or skillfully executed, but no more than that. You did not 'breath life' into the piece. You didn't 'sell it'. It's hard to explain this without using fluffy metaphorical terms.
Perhaps the problem is that you're too focused on the technical execution, which isn't leaving enough processing power for interpretation. You should know your material so well that you don't need to think about it at all.