I'm sorry to hear you're having some trouble. Your symptoms do not sound cardiac in origin. It is possible you had a small stroke, though if you were evaluated in the ED and they ruled this out it is unlikely. Migraine headaches can cause symptoms similar to what you are having. The shortness of breath and swelling are difficult to explain. They could be due to a weak heart muscle, though this is uncommon in someone so young, but certainly possible. A full neurologic exam and perhaps a visit to a neurologist would be a good place to start. And checking some basic labs is not unreasonable. Best of luck to you.
I'm not a doctor--and I'm sure the doc here will answer your questions soon--but I do want to mention that when you talk about 'numbness,' you are talking about things that have to do with nerves, not heart function.
Since you are describing nerve symptoms on one side of your body, I suspect the right doctor for you to see is a neurologist.
Thyroid issues, low calcium, and dehydration can cause your symptoms.. I have had left arm tingling, as if it were asleep, even when I am laying on the other side and its my top side arm. This occured when my T3 was high (hyperthyroid).
Ask dr to check
Vit D
Calcium
Tsh
Free t4
Free t3
Reverse t3