Anyone have any tips on breaking the need for conscious control in playing a musical instrument?

I’ve always wanted to play a musical instrument, but never found the right one. Despite the fact that I discovered quite by accident that I have perfect pitch (and can tune a guitar by ear), I’ve never had any particular talent for music.

Recently, an acquaintance of mine gave me a harmonica and has been teaching me how to play. To my delight, I’ve discovered that I’ve finally found “my” instrument. The problem is that I’ve stalled in the development of my skills as a result of being unable to “let go” while playing.

I can play the harmonica just fine as long as I have tablature in front of me, and I can even bend notes. But as soon as I take the tablature away, or as soon as I realize that I’ve stopped consciously tracking into which hole I’m blowing, everything comes to a crashing halt. I get a sudden feeling of panic, almost of vertigo, and then I am unable to play.

The guy teaching me says my brain is fighting with itself, that I’m developing the neural connections necessary to play music, but that my conscious mind is struggling against it, refusing to hand over control of the musical instrument. Do any musicians out there have any advice for me on how I might break this mental log jam?