What Does Dizziness Along With Fatigue And Chest Pain Indicate?

I‘m a 27 going on 28 year old Caucasian male 6’2” 294 pounds (Down from 315, making slow but steady progress) Since July of 2017 I’ve been dealing with dizziness, balance issues (often feels like I’m swaying) faint feeling and weakness, chest pain both sides but more frequently over the heart and under the left side breast, palpations, fast heart rate, extreme shortness of breath, and headaches. I’ve seen my primary care doctor, a neurologist and a cardiologist. I’ve had a comprehensive and basic metabolic panel, full CBC, lipid panel, A1C, T4 and TSH, Vitamin 25- D, B12, magnesium, urine culture and analysis. I’ve also had multiple EKG, chest X-ray, CT scan of my chest, CT of my head with and without contrast, an MRI of my head, a CTA of my neck and head, an EEG, and echo of my heart, a 7 day heart monitor, a month and half of daily blood pressure readings and the only abnormal thing was my b12 came back at 990 pg/ml. Every other test has come back completely normal and yet I feel sick as ever. Are my doctors missing something? I’m at a complete loss and it seems so are they. Any advice or direction would be so appreciated.