Thanks for your question on Health Care Magic.
I can understand your concern.
In my opinion, you are mostly having
anxiety related symptoms.
You are too young to have cardiac and Pulmonary causes.
But better to get done ecg and chest
x ray to rule out cardiac and Pulmonary causes respectively.
If both of these are normal then you are mostly having
stress and anxiety related 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.
Avoid stress and tension. Be relax and calm.
Don't worry, you will be alright.
Wish you good health.
Thanks.