Off and on chest pain for months.dx anxiety. been feeling sternum pain when i take a deep breath. echo, ekg, stress, holter fine.is my heart ok? anxiety?

Anxiety Sx ??: What you know is that your heart is not diseased. Without psychiatric/psychological evaluation by a mental health professional it is impossible to diagnose on the internet. I also would need a complete history as your question suggests these symptoms are relatively new. Go get a referral, get evaluation, and follow recommendations for at least 2 months and see if symptoms get better or go away.

It sounds like: Speaking with a therapist to discover the source of your anxiety makes sense. If all the physical tests point towards anxiety it is worth exploring what is at the core of your problems.