Thanks for your question on HCM.
I can understand your situation and problem.
In my opinion your all symptoms are
anxiety related mostly.
Because at your age (23), cardiac diseases are uncommon. But better to get done ecg, if this is normal then no need to worry for cardiac cause.
Get done chest x ray and PFT (Pulmonary Function Test) to rule out
asthma or
bronchitis as a cause for your breathlessness and
chest pain.
If both these are also normal then anxiety is the likely cause for your symptoms.
So better to
consult psychiatrist and get done counseling sessions, try to identify stressor in your life and start working on its solution.
You may need anxiolytic drugs too.
So avoid stress and tension. Be relax and calm.
Don't worry, you will be alright.