Chest Pain, Light Headedness, Pain In Arm And Neck. Done EKG, ECG And Stress Test. Next Step?

Hi From past 4 months I am having varied symptoms of chest pain , heart palpitation and lightheadenes. Its worse when I lie down. It all started 4 months ago when I was about go to sleep, as soon as I lay down I fealt my heart racing, light headness, hot and cold flushes in chest, tingling in hands & legs and very slight chest pain. I was immediately rushed to ER where they did by blodd test, ECG, X-ray all which came normal. Doctor told it was just a panick attack and discharged me in sometime. This episode was repeated in few days and again went to ER. After that I have visited atleast 3 different cardiologists and performed various tests like EKG , ECG, stress test, Halter monitor(24 hrs), Chest PFT test and all came normal. Cardiologists say I dont have any heart related problems and sent me for a endoscopy which again came normal. Initially I was on pantaprazole tablets suspecting GERD but that didnt help. For short duration doctors prescribed anxiety related medicines but that also didnt help much. Recently I did LIPId tests and my LDL was 143 (slight higher), HDL 42, triglycerides 100. When the first episode happened, my blood report was normal and its only in these 3 months that my cholestrol level has gone up. This Could be due to stress/anxiety in not able to get to root cause of the issue. Now I am completely clueless so as what to do as problem still persists although somehow I control my mind to not to panick when it happens. I am a non-smoker, non alcoholer, and vegetarian. I dont have any stressfull condition in professional/personal life and am not over anxious either. Currently my problem includes: 1. constant light chest pain in middle and left side (that radiates to back) which could be related to musculo skeletal as when I stretch in particular position it gets worse. 2. lighheadness, palpitation, breathlessness and hot flushes in chest when lying down (atleast 2-3 times a week). As soon as I sit staright when this happens it greatly releaves symptom although after that it gets difficult to goto sleep. 3. even when heart beat is normal I could constantly feel it. 4. Occassional pain in left arm and neck. 5. general discomfort in middle and left side of chest all the time. 6. Strong heart beat even in light exercises. I was perfectly healthy person before all this started and this is actually ruining my quality of life. Request you to please suggest what should be my next steps. Thanks, Sameer