The symptoms you've described—progressive shortness of breath, fatigue, sensation of heaviness in the chest with exertion, palpitations, and difficulty sleeping—warrant a thorough evaluation, given their potential linkage to a number of cardiovascular conditions, especially considering your family history of myocardial infarction at a relatively young age.
Your childhood history of being "always sick" could be pertinent and might indicate an underlying chronic condition that was present from a young age, which could be contributing to your current symptoms.
In this case, I would first want to assess your cardiovascular system. An initial workup would include:
1. A detailed patient history to better understand the nature and onset of your symptoms and to delve deeper into your past medical conditions.
2. A physical examination, focusing on your heart and lungs, including blood pressure reading, pulse check for rhythm and strength, and auscultation of the heart and lung fields.
3. An electrocardiogram (ECG) to look for any arrhythmias, signs of ischemia, or other electrical disturbances in the heart.
4. Echocardiography to evaluate heart structure and function could be particularly revealing given your symptoms of fatigue and heavy feeling in the chest with exertion.
5. Perhaps a stress test to assess how your heart responds to physical activity.
6. Blood tests to look for markers of heart disease, such as elevated levels of natriuretic peptides, and a complete blood count to check for anemia which might explain your fatigue.
7. Given the palpitations, a Holter monitor or event recorder might be used to capture your heart's rhythm over a 24-hour period or longer.
8. Sleep quality assessment, given your trouble sleeping: poor sleep can contribute to fatigue and cardiovascular risks and can be associated with conditions like sleep apnea.
Your report of rapid heartbeat and fluttering is particularly concerning for a possible arrhythmia, which could be of various types including atrial fibrillation, given your description.
It's important that you see a physician promptly, as only a physician who can physically examine you and conduct the necessary tests can provide a definitive diagnosis and appropriate treatment plan. Please remember to bring your full medical history and any relevant family medical history when you visit your healthcare provider.
Please note that while I can discuss what such symptoms might indicate, this information is for educational purposes only and cannot replace a personalized medical consultation.