I would go back to your doctor and demand some tests. I have been having chest pain for over 2 years. All the doctors I saw told me it was acid reflux, I told my diabetes dr. and he sent me to a cardiologist right away. Had an angiogram done and found out I had 6 blockages and 2 are at 90% and another was at 80%. Gotta have double bypass surgery soon. Don't wait too long to get the results you need. Keep getting second opinions.
Although you are of young age, I would suggest being evaluated further by a physician (or cardiologist). Chest discomfort that is accompanied with shortness of breath, dizziness is always worrisome (regardless of age). If not done already, basic tests should be performed to rule out causes -- which could represent a condition of the heart, lungs, GI tract, or overlying skin/muscles. CXR, ECG, blood work and a good history and physical would be in order to help differentiate what needs to be done. If there are serious co-morbidities (smoking history, high BP, dyslipidemia, history of diabetes, or family history), further non-invasive studies might be indicated such as a stress test.