These sudden episodes of weakness, heavy breathing, and near-collapse require urgent medical evaluation, as they could indicate a cardiovascular issue (like an irregular heartbeat), a neurological condition, or a metabolic imbalance. Because these symptoms can be dangerous, it is unsafe to recommend any medication without a formal diagnosis. You should consult a physician immediately. They will likely recommend diagnostic tests, such as an electrocardiogram (ECG), a Holter monitor to track your heart rhythm, and comprehensive blood tests. Please do not self-medicate; obtaining an accurate diagnosis from a doctor is the only safe way to determine the correct treatment.