Can health anxiety(hypochondria)cause u to imagine symptoms that arent there? keep thinking i have different diseases and then seem to notice symptoms

Health anxiety: may cause heightened awareness of even normal bodily sensations. Attention may be focused on those sensations and then one's imagination might take it from there.

Yes: Anxiety is the result of hidden fears. These fears/anxiety causes normal events to be exaggerated in the mind. If your doctor has assured you that you are well, consult a mental health professional.