Severe pain inbetween the breasts located in the middle like at the bottom of my sternum and i also already don't have a gall bladder so it cannot be that?

Severe = ER visit: Severe pain in the lower front chest or upper abdomen means one should talk with her doctor, and more likely go to the ER. In young adults, chest pain could very rarely be a heart attack. It more likely is something such as myocarditis, pericarditis, other heart symptoms, lung problems, costochondritis (inflamed rib cartilage), pleurisy, stomach ulcer, pancreatitis, or anxiety attack symptoms.