What Causes Breathlessness Along With Sharp Pain In Heart?

Hello. Pls I need medical advice. I hv bin experiencing heart gripping feelings, breathless sometimes, and occassional split seconds sharp pain in my heart. I was asked to do Cholesterol/ECG tests. ECG was ok but Cholesterol was high. Was placed on medication and adviced to reduce my intake of fatty foods. I hv bin careful enough to stay away from fatty foods; yet I still feel tight in my chest, feeling breathless sometimes, the gripp feelings is still there most often when i am lying down. The worst all, i feel very terrible pain in my chest; a kind of ice-cold feeling in my heart whenever i am in an aircintioned room. Pls wot could be the cause of these symptoms?Wot am i expected to do? I am 45.