I am a creature of the night, add one letter and I cover you, remove one and I am hurt

I am a ghost that clings to stones, a whisper born from breaking bones. The sky must bleed to call me near, yet I am gone before I’m clear. I do not live, I do not die, I only breathe when earth will cry.

I sometimes disappear, though I am always around. I am a reflection of what I seem to be. I grow bigger or smaller, but stay the same size. Some say I can affect delivery.

I have no wings but yet I fly, I have no eyes and yet I cry.

Clearly married but I'm a known wanderer. Some might remember an iconic old image of me trying a weird diet to boost my longevity. It's truly a coincidence that many now associate me with being gassy.