Mild chest pain left side. 5. 7 inc!

I am feeling constant chest pain on left side since past one year.In a year i have consulted three repulated cardiologist and one chest specialist all told me muscular pain associated with Costochondritis. However sometime i feel chest discofort and pain when deep breath. I am worried about it when i get rid of this problem. Its really scary for me affecting day to day lofe not able to concentrate office work. I have produced all ECG, LIPID PROFILE, BLOOD TESTS, HRCT SCAN, HOMOCYSTEINE BLOOD TEST, CHEST XRAY. STREES TEST all were normal. last year i was diagnosed viatamin b12 and viatamin d deficiency. Currently i am taking met xl 25,bio d3 max and d venizep 50 once in a day. kindly suggest me for proper diagnosis the issue and proper treatment for this.i am really afraid of this. Yesterday i do ecg that also normal i m going to do stress test and 2D echo. I am 36 male 78 kg, height 5.7 inc