Shortness of breath. Chronic dizziness. Always tired. Had MRI head X-ray chest stomach CBC EKG all normal. I'm 25 and doc says I'm fine. I hate this?

Easy-to-miss stuff. Trust ANA thyroid calcium B12 syphilis bloodwork normal, no fad diet or arsenic; depending on big picture, easy-to-miss items include pulmonary hypertesion, parasomnia/restless legs, sleep apnea, carbon monoxide in home, myasthenia gravis, porphyria lyme. Physician may consider trial low-dose ssri and/or offer trial of intensive aerobic training. Good luck.