How to stop health anxiety lately my head has been telling me my left breast is numb but i can feel pain and temperature in it. is this my anxiety or is something actually wrong with me?

First have a physical exam to know if you have an illness. If not, please see a Clinical Psychologist with expertise in multiple types of psychotherapy to help decide if you can be helped with psychotherapy alone or if you need medication prescribed by a Psychiatrist.

Since you could have both anxiety and a true physical issue, start with an examination. Would handle the emotional issues with cognitive-behavioral therapy and/ or biofeedback therapy. A life coach could be considered.