Thank you for consulting at Doctor spring. I understand that you are worried about a pain in the region of the heart. There are several causes of Chest pain. Some of them are to be considered seriously while others are self resolving. Most causes are chest pain are not directly related to the heart and may be due to the lungs, due to chest wall trauma, back, rib fractures, Breast pain etc. So depending on age, you may consider various diagnoses. The main aide to the diagnosis of Chest pain lies in your history. This includes the exact location of pain, pain in relation to food, quantity, quality, difficulty in taking a breath, pain moving to another area of the body.
Considering that you have fever on and off pain on taking a deep breath, the pain may due to a chest infection or due to costochondritis. Rarely, such a presentation may also be due to Pericarditis which is an inflammation if the layers of the heart. If your vomiting and chest pain are more prominent after a meal, you may have a gastric ulcer which presents as a heart burn.Costochondritis or Tietze's syndrome is an inflammation of the area of the rib where the bone and cartilage meet. There will be redness and tenderness in the area of pain. Although extremely painful, it can be treated symptomatically with the use of analgesics like Ibuprofen.
Another important cause may be due to a bruised or a broken rib which is unlikely unless you had an accident recently or are into combat sports.
I suggest that you visit your doctor to rule out a chest infection especially if you have a cough or are an asthmatic. I hope this information was of use to you.